There is actually a way to prove the age anonymously. Yubikey-like devices support attestation - they can have a private key proving authenticity of a device.
So some organization could release Yubikeys with a certain private key and distribute them in stores that allow only adult customers - like liquor stores or sex shops. Owning a key proves that one is adult without disclosing identity. Keys support USB and bluetooth and can be easily supported on any device.
Also, OS developers should implement simple parent mode - such that parents only need to flip a switch and set a password, and do not have to whitelist apps or websites - the OS should use government-provided lists. You might not like the government, but 99% of parents do not want to bother compiling white lists manually.
You're missing the point. The complaints are consistently that age/children is just an excuse for control. Your comment is ironically, "offtopic". The rage is about forced identification.
Although, pointing out how actual age verification would work won't hurt. It helps to make it more clear that these pending laws are draconian.
That's just one of dozens of ways it could be done, hundreds probably. But ultimately proving that you're an adult is not the point, the point has always been profiling people with the excuse of that. Most of these verifications are done by Palantir shell corps even.
The problem with that is, parents be like:
>Here kid, take my key, go get me some beer.
Everyone everywhere gets forced to deal with bullshit, then the people it is supposed to be protecting circumvent it directly.