Angst fics can help people come to terms with their own grief, begin healing, or give people that good cry that they need.
Smut fics can help people affirm and accept their sexuality. It can help them explore their sexuality in a safe way. They can also just be fun, and having fun is a drastically undervalued way to improve your mental health.
Dark fics can help people face their fears or process their trauma. It can make them feel safer and more secure. It can help them find their courage.
Fluff fics can give people rest and respite and comfort. It can give them hope that soft places exist and that maybe there is one out there for them. It can bring up their mood, which, if they have depression, can be a life saver.
And every fic people write makes someone feel less alone.
Point being, just because a particular thing doesn’t serve you, doesn’t mean it lacks value.
This is not to say that we have to consume all fic uncritically. Of course not. It is just to say that entire “genres” aren’t trash or lacking value just because they don’t serve you.