These are the right questions to ask. I suspect that if one were to follow the money behind who is pushing for this law, those questions could be answered.
If Apple can perform a digital attestation of a derived attribute, e.g. "older than 18", rather that disclosing name, DoB, address to the visited website, it would likely be well received.
But at that point, we're a hair's breadth away from state-corporate fusion.
I don’t know about websites, but one of Apple’s examples is almost exactly that – “older than 21” – for purchasing alcohol (in the US, yes, yes) without giving over all of the rest of the information on your ID.