People with mental illness, how accurate does fiction depict mental illness?

As someone with dissociative identity disorder, well fiction is my worst enemy in terms of representation. It is never portrayed with any accuracy, and most often only used to make a character seem more ‘interesting’ and fetishizes the hell out of it. Y’know the movie Split? Yeah fuck that movie and the person who made it. I wish it never existed, it’s like a personal insult

And before anyone asks, no I have not seen Moon Knight yet. I’m planning to, though