Given this reality, why not create a multiplicity of currencies, all convertible with each other and with different inflation rates? Currently we have a hodgepo

Given this reality, why not create a multiplicity of currencies, all convertible with each other and with different inflation rates? Currently we have a hodgepodge of assets with various interest rates that are all convertible with the fiat currency, but as with the gold and silver standards, we are mapping objects with other kinds of utility, such as houses, onto the financial asset spectrum and distorting those other uses. Interest rates should just be used to efficiently allocate resources across time, and the vehicles we have of doing so are very rough and prone to supply and demand shocks for reasons that have nothing to do with one's value of current time and future time.