I think that could get shot down real quick though.

Accounts/identities that are known to have been shared could be flagged as stolen and now anyone who tries to use it gets burned.

Then the question is, what happens to the poor guy whose identity was stolen? As it is I already can't view half the sites on the internet due to endless captcha loops.

Not necessarily stolen. People desperate for money could be "fronting" the accounts.

yes that too. recently there was a post on the red site saying that they thought the invite tree system worked well.

https://abyss.fish/tree-style_invite_systems_reduce_AI_slop

Many of those are self-reporting, anyway. It's not there to stop bots.