Perhaps make a better point, as written your post seems to imply mental illness is the only issue and social media has no impact on society.
Having raised 3 very successful children my personal experience is that when they grow up they are not equipped to deal with the world directly and all the bad actors who would decisive and abuse them.
This can lead to children doing great harm to themselves, that is not mental illness, that is children not being fully developed and emotionally mature yet.
I raised a very healthy and successful daughter ( young woman now)
Parents ought to parent. Social media is just an inert thing. People on social media is a different thing
Teen aged girls in particular can be very cruel
Inert things do not cause harm. That’s like blaming a gun for deaths. Nonsense