The reason money being “backed” by something mattered is because it prevented it from being artificially inflated i.e. there was only so much gold. Bitcoin for example is a limited quanity of 21,000,000 coins that can be divided into 100,000,000 units for each coin. There will never be any more than that. And we know exactly when the last Bitcoin will be mined (2140). So itself being limited solves the having to be backed by something else.

The reason money being “backed” by something mattered is because it prevented it from being artificially inflated i.e. there was only so much gold. Bitcoin for example is a limited quanity of 21,000,000 coins that can be divided into 100,000,000 units for each coin. There wikl never be any more than that. And we know exactly when the last Bitcoin will be mined (2140). So itself being limited solves the having to be backed by something else.