Don’t get me wrong, I’m all for privacy. But between setting up the birthdate when creating my children’s local account on their computers, and having to send a copy of their ID to every platform under the sun, I’d easily chose the former.
I’d even agree to a simple protocol (HTTP X-Over-18 / X-Over-21 headers?) to that.
I do expect it to change. I expect it to be standardized with zero knowledge proofs. If I am avle to communicate with you on a random internet forum from anywhere in the world using standardized protocols, we can get private and secure “I am 18+” verification. It may initially start with proving it in some form or another, but if done correctly you would essentialy have a private key that certifies you are over X age. The company would know nothing about you, other than you are not a child. I have extremely simplified it, but it is possible.
Many OS here aren’t made by companies. They can all easily just be forked and edited to immediately wave people through any hypothetical age checks, moreover any website could just ignore it and wave everyone through.