For the average Joe, currency was only a yardstick to standardize barter transactions anyway, for most of human history. Currency was for governments and travelling merchants, not townsfolk who stayed in one place and knew the same people all their lives - townsfolk just traded with each other, and maybe kept debt books, but only strangers needed to pay coin.

Of course, this only works in small populations in high trust societies.

The industrial revolution really was the worst thing to happen next to the Renaissance ....