It’s using bitcoin to back up PoS chains and you get paid back in PoS coins, not bitcoin. Except right now. Apparently you can lock in now but can’t stake yet so I don’t get the point. Either a lot of people fell for this or something in the code fucks the mempool with only a small amount of these “staking” activities. 

https://image.nostr.build/0948839dfb5d98a0942aad13bb8bd33548772f63ad0003f32a2e61dbdc1fa253.jpg