Ok, regarding #bluesky and #missisipi, #uk, #australia I think a great opportunity for age verification would be a company using something like @badgefed , where there only purpose is to do physical world credentials verification, and then emit a decentralized badge (18+ years old) and then companies can just use that badge to let them login.
I mean, if the badges are emitted to fediprofiles, they can even login with their accounts!
Dreaming awake I know.