> system akin to film classification age ratings

I am pretty sure that most parents let their kids watch movies that are rated for a higher age group then their current age.

For example a lot of marvel movies, harry potter or pirates of the caribbean are usually in this category.

My conclusion the parents are not lazy they care to be breaking the age restriction. A lot of parents even go out of their way or get aggressive to make sure they can age rated movies to their kids as they think the age ratings are bullshit.

I would suspect age verification to have similar effects in practice, and there is the additional hurtful factors as well leading to a net negative. Not just for minors but also for adults that now have to deal with this crap.