Generally speaking that should be the goal, but I started watching porn when I was pretty young and would do so again if I had to start my life over. It’s up to parents to stop that kind of behavior, not the government.
Generally I think there should be zero regulation on age verification for things like porn and other “adult” content.
It’s the parents job to police their kids, not the state. Any government regulations regarding age verification would likely infringe on our rights.