Cashu doesn't pretend to be Federated, so in that way it's not scammy. It's custodial tech, which is fine if transparent.

Cashu is simply retarded on a technical level, that's better than being a scam though.

The knock on Cashu is that it's overly complex and the only appeal it has is to virtue signaling privacy larps that think you can get privacy from a custodian.