Nominal prosperity maybe, not in real terms.
Real prosperity and it's not measured in money. Money is just a social construct it's not a source of wealth. We don't accumulate money for money's sake, we do so in order to exchange value and meet our needs and desires, whether that's wine, medications, touring bikes or blobs of bullion.
Prosperity is measured by access to health care, transport infrastructure, education, clean drinking water, leisure activities, social institutions, cultural and sporting pursuits, electricity, heating, refrigeration, communication, life expectancy... Do you want me to keep going?
A Mitchell Innes said:
The monetary unit is merely an arbitrary denomination, by which commodities are measured in terms of credit, and which serves, therefore, as a more or less accurate measure of the value of all commodities.
Fiat that is devalued from day one and requires interest isn't ever sustainable.
Why not? It's not as if it actually exists. There's an unlimited supply of the stuff. Sure there is a minute fraction of the physical representation of money moving around the economy in the form of notes and cash, but as has been the case for thousands of years the majority of exchanges take place on a ledger ie virtually. An economy that is restricted to using a finite supply of money based on a limited supply of hard currency is an economy that will stagnate and eventually disintegrate.
Sure the first 30 or 40 years of a fiat life cycle is always great until reality comes and people can see how poor they are, like right now.
As A Mitchell Innes in 1913 and others hundreds of years before him argued, how people tend to think of the way our monetary system is constructed is built on falsehoods. It's not what it seems. There's a lot of misconceptions floating around on what money is and what it has supposed to always have been.
A Mitchell Innes said:
Money, then, is credit and nothing but credit. A's money is B's debt to him, and when B pays his debt, A's money disappears. This is the whole theory of money.