>parents will give their children their unlocked account, and children will steal their parents' unlocked account.

I think either is better than the staus quo. In the first case the parent is waiving away the protections, and in the second the kid is.

Even if a kid buys alcohol, I think it's healthier that they do it by breaking rules and faking ids and knowing that they are doing something wrong, than just doing it and having no way to know it's wrong (except a popup that we have been trained by UX to close without reading (fuck cookie legislation))

That would be the status quo if we had better parental controls.

Trying to enforce parental controls via regulation may only be as effective as Europe enforcing the DMA against Apple. But maybe not, because there's a huge market; if Apple XOR Android does it, they'll gain market share. Or governments can try incentive instead of regulation (or both) and fund a phone with better parental controls. Europe wants to launch their own phone; such a feature would make it stand out even among Americans.