A 16 year old can, in most cases, be legally independent of their parents: living on their own. They can also, in many states (and countries), legally give consent for sex.
But we shouldn't let them view user generated content?
The inconsistencies don't even end at adolescence. You can die for your country at 18, but you can't buy a drink or (since 2020) a smoke until you're 21.
But we shouldn't let them view user generated content?
Seems inconsistent at best.