As currencies have existed for thousands of years, then I guess it took all that time to bootstrap to a half century ago, where the currency started running on air.
Or -
A few years or decades from now, our post Bretton Woods, post Gold Shock currency system will become untenable and be replaced by something else, as has happened numerous times throughout history, especially when the currency has no inherent value.
Or -
A few years or decades from now, our post Bretton Woods, post Gold Shock currency system will become untenable and be replaced by something else, as has happened numerous times throughout history, especially when the currency has no inherent value.