> ultimately that removes the ‘fraud load’ by mostly moving it to another place, to number of accounts. That is arguably worse because it incentivises the malicious users to create as many account

Arguably the common social media policy of not having your account tied to a unique identity needs to change. It permits all sorts of problematic incentives like you describe, and which lead to bot accounts and more.

Of course, your identity doesn't need to be disclosed in your profile for when anonymity is important.