My parents always kept a few bottles of wine in a cabinet in the living room. If 8 year old me wanted wine, I could have drunk a whole bottle while they were away and there was no way they could have stopped me. Yet I didn't drink my parents' wine, nor did I grow up alcoholic.
You could and when you would end up in the hospital your parents would have gotten a visit by people with sticks.
You can let your kid play in traffic. You can let your kid run around with knives. Sure, but when shit hits the fan you'll be luck to pay a hefty fine and lose all social credibility you had. In the worst case you're looking at jail time. Those sort of incentives will tend to smooth these issues out.
Kudos for resisting alcohol as an eight year old. How does that apply to all the kiddos whose lives are impacted by social media? Kind of a "them problem"?
Yes, it is. Kids get screwed up in all kinds of ways that we do nothing about. We could eliminate a lot of harm by prohibiting religious indoctrination, for instance, but that's unlikely to happen.
There is no hard data showing that religion (which one? all of them? from learning the Tao to following the dude who said "Love thy Neighbor"?) is somehow harmful, but we have direct evidence showing this is harming children. What is with people ignoring data and facts because they're scared of something largely innocuous? We get it - you were bored when your parents made you sit in a pew for an hour a week.