Fortitude and coping skills are learned through adversity (sometimes with the help of parents or a therapist, most often with a lot of hopefully lower cost failure), but suffering you cannot grow from is unnecessary and not of value. With that said, social media is an unnecessary toxin children and teens are exposed to. You wouldn’t let them bathe in PFAS, and social media is similar: ubiquitous but also toxic with extended exposure.

> it could be an indicator that people are less able to cope

That would mean life is worse. And we can measure how much worse in suicide rate deltas.

No, it would mean that one specific part of life is worse.