If you could do that effectively then what is the point of spending money to upvote?

Also look into the current state of play to earn games [1] and some NFT auction methods where people are selling their participation quite openly [2]

It’s no longer a Sybil attack if it is real people who value their moral “vote” less than the market rate of that vote. It’s just an open market encouraging wealthy participants to on-board buyable users.

[1] https://restofworld.org/2021/axie-infinity/ [2] https://www.coindesk.com/layer2/2022/04/29/please-dont-buy-a...