Once a good is established as money, no additional quantities of this good are needed. The performance of an economy is independent of the supply of money.
Inelasticity of supply is no hindrance for a commodity to be used as money. Or to put it differently, there is no basis for the widespread belief that somebody has to meet the growing demand for money in a growing economy.
Within reasonable limits, any quantity of money is optimal. Money production is redundant. Supply and demand for money can always be brought in line by changes in money’s purchasing power.
Ongoing money production is simply not needed. It is not true that society needs a money producer who can satisfy changes in money demand and that it is probably best to entrust this role to the state. Money was not invented by the state, and it is certainly not a “natural monopoly” of the state. Money has evolved organically and spontaneously from the voluntary actions of trading individuals. Once the market has identified the suitable monetary commodity, no further production of this commodity, nor any other adjustment to its supply, is needed.