For every debt there is someone holding it as a credit. Unless the lizard men space alien conspiracy is correct and they will come down with their space weapons

For every debt there is someone holding it as a credit. Unless the lizard men space alien conspiracy is correct and they will come down with their space weapons to enslave us if we don't pay, this is just digits in a computer and can disappear in a wink of and eye (or revolution). As for the currency idea, that is already how dollars are created. A bank loans out money it owes other people and creates new money.