alt Hacker Newssimple solution: go to a convenience store. Show your id, maybe 2 pieces. They frown, shrug, and give you an anonymous verification token, usable once (or maybe a set of 20), that you can then use to anonymously verify your age.
Yeah, people will sell these tokens online, but that's not the end of the world. People have bought liquor for minors who sit around the corner from the liquor store since forever. It's still a reasonable comporomise
This is a perfectly reasonable solution if the problem really is child safety. But we all know it's not. There's money in surveilance and profiling.