Why wouldn't criminals like they do now just use stolen identities? If someone verifies they are a person that doesn't mean they're not leaving their PC on with some AI that uses their credentials either.

The point of these systems is not to ban any possibility of fake accounts. The point is to add friction so that creating accounts is harder than banning them, so criminals can’t recreate them at scale. Otherwise bans take seconds to overcome and a single person can run 10000 automated identities.