Cultures around the world have barred children from certain social places until they go through a rite of passage that the whole society, not just the parents, recognize.
Yes, cultures around the world have done this through parents parenting their child successfully, and not through arbitrary government overreach telling you how to parent.
Not really. The ideal you are describing, where there is no role for the community in regulating public spaces outside the household and determining when young people can enter them, strikes me as highly unusual historically and geographically. It’s an example of that streak of libertarianism that took off from early American internet culture and hardly exists outside internet pontificating.
