>$17B worth of crypto.
Ah, so there are Bitcoin "backed" loans but they are denominated and paid in dollars. The supposed "value" of Bitcoin in dollar terms is what serves as collateral for these loans.
Here is a hint: price does not equal value, especially when it is as volatile as BTC price is. So essentially these are unbacked loans...
If BTC eats the dollar in the future, e.g. under USD hyper inflation, then BTC x USD creditors are still screwed like all other creditors lending dollars. Their debtors will be able to pay the loan back with depreciating dollars.