Yes there are "bad" things children can be exposed to. But the difference is the lifelong real trauma caused by sexual abuse. Yes kids can learn lying from the internet, or see people smoking, etc. But if you are a pre-teen that sexually abuses another pre-teen (which happens _very_ common surprisingly) it has an enormous capacity for harm compared to other "bad" things. With this and that it's much easier to regulate, I think it is worth the trade-offs.
If you mean barring general access, than your evaluation is debatable.
But especially:
if the concern is with some forms of possibly "certified traumatic" depictions (and I believe this would raise a hell of a needed research and nuances revelation),
why not just attacking the "certified traumatic" depictions?
