I'm gonna be one of the few to voice my agreement with the OP..
And to it I would add: maybe if the advice seems 'delusional' or detrimental to you, maybe it's not actually that it's inherently wrong, but that it only works for a certain kind of person...of which I am one.
And the reason I know it CAN work for some people is the same reason I know that most people can't use it...long story short, a lot of the issues with insecurity, fear, and anxiety that are apparently common among artists from this forum alone...they simply don't affect me in any way that matters. I read through them; I can understand how bad it must feel to experience them...but I can't actually relate. As I always say, I have a pretty big ego, and I always have.
And it can do a lot to protect you, as long as you're realistic about it. So many people who've replied to this thread assume that an artist who cultivates confidence in their work simply can't be open to criticism, or won't be able to take criticism when they finally start to receive it. Which isn't necessarily true. Personally, I think all my pride actually saved me when I started to receive criticism, especially when it came from bad sources.
Probably the most insecure I've ever been was when I was 16/17-ish, and my biggest artistic role model at the time basically told me that anime-style art (my bread and butter) was fine to play around with, but that no one would take it seriously when I grew up. And after that, whenever I would hear people making fun of anime, I took it to heart just a little bit more.
Then I wound up in that IB Art class...I'm not really in the mood to talk about it now. But yeah, hearing people dismiss and degrade the kind of art you'd loved all your life would probably have had more serious repercussions for a less-confident artist...for me it just motivated me to show off more of what I could do. After all, when you're the 'best' artist, you have to be the best in any category. And anyone who decides you're 'lesser' for any reason has to be made to eat their words. >:[
Of course...in hindsight, I realized that it's impossible to change how your artist brain works in just 2 short semesters. ^^; All my work was 'good', as usual, but many of the pieces ended up being used to board up the floors...it's hard to have passion for art that you're working on out of spite. But that's all I have to show for that experience; a few spite paintings and some cringy memories; not ongoing trauma and anxiety issues. And I thank my ego for that.
Now, to argue for the advice itself: yes, it's important to get used to the idea of receiving criticism as early as possible, but I think it's also important to go for long periods of time without criticism, especially in the beginning.
Most beginner artists, even ultra confident ones like myself, already know that their work isn't exactly like that of whoever their inspiration is at the time. So hearing that from other people is not helpful.
And hearing actual criticism along the lines of 'these are ALL the things that you're doing wrong, and how you need to improve' isn't actually that helpful either, because that list would be pretty goddamn long.
Who needs that kind of stress when you're just 11 or 12 years old?? You're better off just drawing by yourself and waiting until your skill improves naturally, and you get to a place where most criticism can boil down to smaller, more specific problems.
That isn't to say that beginner artists can't ever be criticized...I just think they would need a critic with sensitivity to where they are in their journey, as well as insight into what kinds of criticisms will actually help them to continue learning, not just saddle them with issues that they have to figure out how to solve alone. And seeking criticism online, from the general public...is NOT likely to get you that. Full stop.