What are some use cases? Someone downthread mentioned loaning money where 150% of the money is put in escrow as collateral. This didn’t make any sense to me. B

What are some use cases? Someone downthread mentioned loaning money where 150% of the money is put in escrow as collateral. This didn’t make any sense to me. But some of the smartest people I follow are hyped about Defi. So....what can you do with it? Or could you do if adopted.