The cookie dialog was a mistake -- this is something that should've been handled as a browser API. A standard dialog of "do you consent to cookies yes/no/functional-only" should be part of the HTTP headers.

Same thing with age verification. My kids all have devices that are managed through parental systems like Google Family Link and Microsoft Family Safety. It would be straightforward to have a header for "user is an adult" or not, and to have a standard API for "this site is requesting metadata that you haven't said to automatically make available without permission. Do you want to send it? Y/N [ ]checkbox use this for all sites.

The only time we should even be talking about full identity verification is on user-submitted content, and even then that should be up to the site (with the commensurate legal liability of hosting anonymous slop).