Ah! Good question!
First, I don't think you HAVE to throw away your first ideas/draft.
It really depends on the way one constructs their projects. It's probably more likely to happen with projects with a long genesis.
It's not a necessity, but something that may happen to be the good decision in certain cases.

If the ideas NEED to be dumped, I'd answer: new ideas and a good deal of time.

My current project was first a music project (concept album type) and changing it into a comic forced me to change a lot of things. I'd say I 'mourned' some of the original ideas for about 3 years. From time to time I was still wondering if I should not reintroduce some of these ideas, or I would worry that I should have, in cases where it was too late already.
But recently I listened again to the (unfinished) music project and I did not feel any sadness anymore about the 'dumped ideas'.
The new ones I had to replace these parts slowly grew on me, and I can now appreciate how they fit the project better.

One thing to consider too, is that ideas are recyclable.
Dropped ideas can be cannibalized for another project.

I think that you mistake 'hate my art' just for the sake of hate it, than hate it because you now know more, and can change some parts of your original idea to adapt the knew you. You don't have to hate your art just because a tutorial said so, you have to do it for a purpose. And for that purpose you don't only have to leave the work aside for a couple of months and come back later to check if you still like it, you have to also grow with new ideas. Read some novels, comics, watch movies, tv series, and things that you even may not like, check tutorials from differents parts like YouTube, Domestika, to understand the basics of everything you may need or just for fun, then when you check again your draft you can say 'oh this was just like that scary movie that I hated that much o_o', or 'oh, with this watercolor technique I can do this vignette like 100% better'.

Now if after all that, you still don't want to change a comma from your piece, there is no problem either. There is no golden rule that must be followed. You just need to follow what you feel works for you, and if you feel that your original work is good, then go for it. When its all said and done, you can get some precious feedback that will help you on the long run and will not be lost time.

I think if you are operating under the idea that you must hate your ideas, is setting yourself up to fail. You might not be 100% in love with every single idea but you should be willing to recognize that you can learn from your ideas and be able to mix and match ideas into a plotline.

In regard to "killing your darlings", the only times I think you should "kill" your darling is either when there is nothing more they can add to the plot (tapped out) or their death adds to the emotional impact and affects someone else's arc. Other than that, put your characters through the wringer but realize that the struggles you put the character through can create new struggles for other characters.

For example, my main character is recovering from a tramatic experience from the prior story. In addition to my MC's struggles, the event has also been hard for her loved ones. Her father is struggling with watching his daughter in pain and his adopted daughter in a coma, and he can do nothing to help either of his girls. One event = lots of character development.

I don't know if many people actually do that...I know I certainly don't.

It's usually more of a process of systematic decay...like, I have a bunch of future ideas I wanna use, but as the story progresses and I make various smaller choices along the way, some of those future ideas become less and less viable (like, for example, a future redemption arc for a character whose crimes are currently getting more and more heinous...). Eventually I get to a point where certain ideas just won't work anymore, and there are plenty of new ideas to take their place, so they get the axe. ¯_(ツ)_/¯

If I had to guess, I think either you're (a) a careful planner who doesn't leave a lot of leeway for your story to unexpectedly change as time goes by, or (b) you just know what you want. Which isn't a bad thing.

I think the reason things like 'kill your darlings' can become bad advice is because they assume your first ideas are bad ones simply by virtue of being first, which is really only supported by experience, if anything.
People improve their stories with time, and they also get new ideas with time, so there's correlation...but not necessarily causation. ^^; There's no reason you can't stick with one idea and simply make it into the best version of itself over time.

I don't think many authors hate their ideas at all. Cultivating such a mindset sounds like a good way to poison yourself against ever wanting to write anything. You should love what you're doing, even at its roughest stages!

My stories look quite different now to how they did 5 years ago not because I hated parts and threw them out, but because I recognised what was incomplete and let it evolve. Sometimes, that meant adding or removing a character, or cutting a scene or ideas I liked; but that happened because I liked the new idea even more, (or because it simply makes more sense in the context of the plot), not because I liked the old idea any less.

I completely disagree with the notion that your first draft is "never good." Sure, it's more likely to have some kinks to work out in the early stages, but it's also just as possible to go into the story knowing exactly what you wanted from the start. Quite a few of my own stories, in fact, changed very little from the first draft.

I also feel that "kill your darlings" is really situational advice. It really only applies to the very specific scenario of "well, I really like this character/scene/whatever, but the story as a whole would be improved if I were to remove it." If there's nothing wrong with the darling, there's no reason to kill it. And you shouldn't force yourself to hate your own writing just because some random person on the internet told you to.

Do you really need to feel like your first draft is awful and you need to hate it? Being the complete opposite of you, and needing to rewrite constantly, I find it admirable how you're able to like your initial idea and keep it! I wish I had that ability. It would help me tremendously in finishing my own stories. Sure, it can be good to fix things, but you don't always need to.

Perhaps you've just got a good idea of how your story should be? You should always go with your gut, so if you think that cool twist is good, then you should keep it. You could always try finding someone to critique your work if you've got any doubts too.

If you tested out the other ideas and it didn't feel better after you tested them, then they weren't better. That happens a lot.

Kinda like how in school we were taught to make like pages and pages of concept art drafts before moving forward with illustration--no one has time for that in the field. You make 2 or 3 and then you need to move onward. There's a FOMO with what could have happened, and I don't think it's very healthy to dwell on "what if" too long when it comes to our own creations. They are what they end up being.

Like building a poker hand, it is better to have a hand that is legal and finished, then to have no hand at all because you tossed your lower number cards out hoping you'd pull a full house. (Is that poker? I've only really played poker on Dragon Quest so I don't know how it works with the bluffing and all that. TBH this analogy works better with Mahjong hands.) And, like a poker hand--all cards are worth the same individually, they only gain worth because of what they're next to--and sometimes you need time to build what's next to that moment in your story to see if it's turning into something or if it's just not. It may be that it's too early to tell if this part in the future that you're worried about will or won't be in there.

I agree with a lot of the comments above, BUT if you want to make a purge or see if your ideas will be worth it, find yourself a writer buddy or testreader to bounce ideas of of. Sometimes you stare yourself blind on your ideas and you won't be able to see their flaws anymore, especially if those ideas are near and dear to your heart. Having someone you trust to tell you that you should really rethink some aspects helps enormously.

Make a character then off set their perfections with flaws. Note that flaws don't need to be very visible. i.e. Making the nice girl a secret nazi might be attractive and very interesting if done correctly but flaws lie in the nuance. Also try to imagine characters as actual people that you might have known. That way your mc who might have for instance been a Mary sue with no hate in her precious heart turns out to be that 'fake' kid with whom a five minute conversation turns out to be a chore.
I write characters first so that helps me.

I think this sort of stuff tends to be overthought. The "writing advice" industry is populated largely by people in the traditional publishing world, who are trained on literary work and books being defined largely by their genres and all that sort of stuff. And one thing I've noticed from that sort of sphere is that people seem to think that first drafts are always these bloated whales that need to be chopped down into zippy little market-friendly dolphins.

But, I don't know. First drafts are basically always bad, yes, but it doesn't mean you need to throw a bunch of stuff out. Sometimes it means you need to ADD a bunch of stuff, which is almost universally what I do when I revise my work. You shouldn't remove anything you don't hate, so if you like or love a part of your story, then that's exactly what you should double down on. Because you loving your own story is much more important to its future success than anything else. You'll always know the flaws and feel dissatisfied with your final drafts, just like all authors, but as long as you know the parts you love, then you'll surely be fine with letting the whole world see it.

So the way I do it, which at least works for me, is I tend to categorise scenes or events as "things for me" and "things for my audience".

I keep every scene I write. They all exist in text documents somewhere or other. Some of them I personally think are really cool or emotionally satisfying and I'll revisit them... BUT I also recognise that often these scenes don't work in my main script because:

1. They take too much explanation to be as enjoyable for the audience as they are for me. I know all my characters full backstories, family history, everything about their personalities and what they like, so there are scenes I might write that are super meaningful and emotionally intense to me, but to be the same to an audience, I'd have to have so many supplementary scenes to establish the context that makes the scene good, it'd just bloat the story.

2. They're too self-indulgent. Like all creators I have certain things I like. Characters making dramatic entrances, timeskips, characters who think they're beyond redemption being redeemed, people having long, rambly conversations about one thing when they mean another, anti-climaxes... In moderation, all these things can be fine or even good, but sometimes I just want to indulge in this melodramatic cheese to a level where it'd just be unbearable for an audience.

So I don't "kill" my darlings, I just "cut" them and shelve them somewhere. That scene was fun for me to write, but it won't be fun for somebody else to read, or it was fun to write, but do I really want to draw an entire sequence of several pages of the characters talking about a fictional shounen manga they used to read that is actually a metaphor for their relationship, when visually it'll be just them sat in a room for 4 pages? It can sit in a text document and I can revisit it when I want without subjecting my readers to it.
It's just like recognising that I have a tendency to ramble in conversations and teaching myself to stop when people look visibly bored. Could I monologue about Final Fantasy VIII for half an hour? Oh yes, I could! And I'd enjoy it! Should I go up to people at parties and monologue about FFVIII for 30 minutes? NO. That ramble is better just kept in my head or shoved on a blog or said to my partner who will spend most of it trying not to laugh while looking at their phone and then lovingly tell me I'm a dork and they enjoyed letting me passionately ramble because I was clearly having a great time.

So basically, feel free to make the things, but then be selective about which things you present the audience so that they get the clearest version of your story. You can then always show these "deleted scenes" as extras if you get people as passionately invested as you are.