I don't believe it's something for the government to enforce. Any law that requires a nongovernment agency to collect identification means that identification is at risk of being stollen and means it will be used to track the person. If every person using the internet will have to prove their age everywhere, it's going to be a mess.
Whatever company has the worst security will have all the IDs stollen and used everywhere else. And I'm sure at first, it will be used so that criminals can frame others for their online crimes really easily.
I mean how do you prove the person using the internet is the one in the ID over the internet. It's easy enough to just use the picture on the ID and some "AI" to produce a fake image if they're going to require taking a picture of who's using it or something like that. This won't stop any minors from accessing information they shouldn't. The only way to do that is through education to make them realize they don't want to access that information and then give them the tools to avoid it. Not try to keep it from them. That just makes them want it more and to have to become criminals to do it. And further, if they're committing that minor crime just to do something normal it desensitizes them to more serious crimes because they don't understand the reasoning for them. Which is why making minor stuff that doesn't affect anyone but the offender a crime is always a bad idea.