Depends, the EU seems to actually have a decently prepared system, using zero knowledge proofs. If it's that, my privacy would not be harmed, but would still prove I'm allowed to view the page.
As for the situation where every site needs a photo ID, I might just go live in a cabin in the woods or something
Edit because I'm being downvoted: I do not support the idea of locking down parts of the internet behind any kind of identification. The question is "what would you do if it happened" not "how would you like to see it implemented".
Young children should absolutely not have a phone, unless I suppose it's completely locked down to chat apps and the tracking I suppose...