No doubt that it could fail. Very very hard problem.

It would be hard to know how many fake proofs are out there. I hope Worldcoin more clearly communicates that people should not treat this as a pyramid, and if people do, I can't blame Worldcoin. The line between a referral system for early adopters and a pyramid scheme can sometimes be tricky to define (ex. People were saying Tesla's referral system and stock hype was pyramid scheme-y).

I still think Worldcoin has proposed the best solution for attempting to solve this problem. Perhaps their solution might have fake accounts, ~1-2% might be acceptable. Nonetheless, I'm hoping that others go after this problem by seeing Worldcoin try and tackle it.