Fiat money depends on laws to enforce, rather than to forbid, usury.
Usury is a sin and it used to be a crime. And a crime it will be, again.
The "crime" of usury was defined long before the appearance of fiat money. With official inflation approaching 9% and unofficial, but more realistic, inflation at close to 20% there are very few willing lenders at lower interest rates.
The laws of economics will always trump the laws of man.