This is why "large scale action" e.g. from school or better regulators are needed and why parents only can act very limited.
Don't force social isolation on your children just because idk. "this game is bad". Even if they social circle is "good" and doesn't start excluding or harassing them because of this (totally can happen, you can't really choose with whom you are in a class) it still is leads to a subtle isolation which might by itself not cause any mental issues, but can amplify existing issues, prevent mental scare from being healed etc. And such issues don't always come from "big bad thing" sometimes small bad things wrongly processed as a child can be enough to cause life long mental issues if the child has never the chance to reprocess/recondition/overcome them.
EDIT: Just to be clear doesn't mean children should have unchecked social media/game/etc. access.