But that's starting to change (https://centrifuge.io/) - still a long way to go ofc. I also know people who have done non-crypto collateral or just completely unsecured lending, but it does involve trust that is off-chain (legal contract, know the person, etc). I think that's a fine stepping stone (and may end up being necessary) as people figure out how to do everything on-chain and in decentralized ways (ex. using on-chain reputation)