The difference between a market economy and capitalism is that markets need money to circulate, while people tend to see it as signal, to extract and store. We are linear, goal oriented creatures in a cyclical, circular, feedback generated reality.

So money functions as an accounting device/social contract/medium of exchange, enabling complex economies, we see it as signal to extract and store.

Econ 101 calls it both medium of exchange and store of value, but one is dynamic, while the other is static. Blood is a medium, fat is a store. Roads are a medium, parking lots are a store. They really should not be mindlessly confused, or we end up with a situation where most of the money is being wagered against other money, than actually sustaining the actual economy.

To back the asset, similar amounts of debt have to be generated. Much of the basis of our wealth is public debt that was spent blowing up various other countries. It's a ponzi scheme.