It's not really a matter of it entirely solving the issue. As the other commenter is trying to stress, these are 2 separate issues, even if 1 underpins the other. We can and should try to solve for both. The thing is, 1 is a heck of a lot easier to solve. So why wouldn't we?

I don't think the position of "Having more accurate pop culture depictions of mental health issues and disabilities would enable better understanding from non-disabled people" is an entirely crazy one, and you haven't really made any arguments as to why we shouldn't do that.