No one is doing it that way though. Also to be truly privacy-preserving you cannot rely on anything that requires any specific OS (especially Android or iOS) as every single OS requires some compromises to privacy.
The only privacy-preserving (effective) age verification is asking user if they are over 18 and requiring that they answer truthfully under penalty of perjury. Then prosecute the kids who claim they are over 18. For reason or another no one seems to be pushing for that option.
Well it exists in Privacy Pass, which is deployed in production. And there are countries that are currently actively looking into privacy-preserving age verification. I don't think that "I keep saying that age verification fundamentally leaks your ID, which is wrong, but it's still valid because nobody will notice" is a good argument.
> The only privacy-preserving (effective) age verification is asking user if they are over 18 and requiring that they answer truthfully under penalty of perjury.
I disagree, I think that there could be a sane debate around ZK age verification, if we could elevate it to that.
It is possible to do age verification in a privacy-preserving manner. So... you're wrong here.