Drawing I think is more concrete and tangible, especially to devour. You can go on ArtStation and look at the cream of the crop, e.g. the artists that have been in the industry for a long time, with calibre of experience to compare to your own. It's faster to make that comparison. Everyone starts nowhere though mostly. No one sees the process it takes to get to that level. So beginners, I think, growth or thick mindset aside, depending on their personality and understanding of the craft or any craft, they will feel discourage or not.
In example, if said person had played basketball before, and is able to perceive growth and development overtime, and that no one starts off with a built body and excellent cardio, that has to be built. Then they will have an easier time taking on new crafts, like art, or writing. 'Cause there's already that inherent understanding of, it takes time.
We can talk about plateauing and all of that, which, it is subjective in ways, and how we feel about our own art and writing. But, by that point, most artists would have already the understanding of, more study, more practise, and more looking at what others are doing, will generate some progress.
I can only speak about my own experience about drawing and writing. I definitely was terrible at the beginning, it is what it is. I don't think I'm that good now, it's just more like, so much time have passed, and I feel like I've studied so much, that time I've spent on the crafts is lost on me. In the moment, it feels like you've always were 'this proficient', even though you know in reality, you spent a lot of time on it. Though yeah, getting to the level I would like to be at, is, I think, I don't know how long it will take for me to get there. Slow progress is enough for me.
When it comes to writing, I think, the thing is. A lot of novice writers, they don't read enough. So they have no true reference of what is 'good' or not. If you've read Lightlark, or Fourth Wings, and you haven't read much others, you may think it's good and the best thing ever. I don't know those author well enough, I just feel like they haven't read much either, otherwise they'd be able to perceive their own shortcoming with said works.
Reading is somewhat a chore, yes. It's difficult to find things you like to read yes, some people are like that. I'm not different, but some people will completely disregard the importance of reading others work and just start writing their own. Which, I don't think is 'incorrect', as long as a writer is having fun and what not, that's passion, is it not? At the same time, if the goal is to become a proficient writer, I'd say, people whom don't read as much as they should, don't know what proficient writing looks like.
We aim and strive for some 'image' or 'vision', we have of our art or writing. When it comes to writing, some people don't have that vision or image, how can they? They've read 3 to 4 books in their entire life, they enjoy writing literature in the sense of devouring stories through other mediums like cinema and visual novels. So they understand stories on some level, but they don't understand literature as a medium. I think a lot of writers fall into this trap, it's apparent by the level of work that are trudged out.
At the same time, worldbuilding, is difficult work, it is in itself a facet of writing that requires A LOT of practise and thought. If you were to write a setting in our real world, and don't need to worldbuild one, you've saved yourself TON of work. So Lightlark and Fourthwings, have a disadvantage that Twilight does not, all Twilight had to do was worldbuild the vampire society aspect of it, Lightlark and Fourthwings had to worldbuild a whole fantasy world. And it's obvious, they didn't practise much. But characters are universal though, so, there's no excuses for shortcoming in that regard.
Writing, I think is so much more subjective, when it comes to, 'what is good?'. And that subjectivity derive from the references we know. Some people didn't fall in love with writing because they read things, they fell in love with writing because they love stories, and writing is the easiest medium to create stories within. Compared to making manga/comic, it's like, forget about it, writing is far far far easier to dive into, and don't take as long to generate something 'good'. With drawing stories, you have to learn 10 fold I think, to even start, and even then, you'd still have to understand plot, characters, etc etc.
Which is all to say, some writers, they don't improve because all they do is write, if they studied the technical aspect of writing, and read literature, they will greatly improve in ways that they cannot by just writing more. There's a good balance to be had, of studying the craft and practising the craft itself. I think anyway, for 'most'. Maybe veterans aren't so much on the study side of things anymore, but I know, they still read literature on the daily, to see what others are doing.