Actually there is, various age verification systems exist where the party asking for it does not need to process their ID, like the Dutch iDIN (https://www.idin.nl/en/) that works not unlike a digital payment - the bank knows your identity and age, just like they know your account balance, and can sign off on that kind of thing just like a payment.
I hope this becomes more widespread / standardized; the precursor for iDIN is iDEAL which is for payments, that's being expanded and rebranded as Wero across Europe at the moment (https://en.wikipedia.org/wiki/Wero_(payment)), in part to reduce dependency on American payment processors.
I hope this becomes more widespread / standardized; the precursor for iDIN is iDEAL which is for payments, that's being expanded and rebranded as Wero across Europe at the moment (https://en.wikipedia.org/wiki/Wero_(payment)), in part to reduce dependency on American payment processors.