Yes, I couldn't imagine how difficult it is to manage at scale. YouTube Premium is my favorite a-la-carte service that I pay for but I don't know how it would cope with adding that level of protection.

I suspect YouTube's goal is to add maximum protection for children either way. It's a massive liability and ethically the right thing to do.

I find that the more tech-savvy a person is, the less they let their kids use social media and YouTube lol. They know how dangerous it is.