"Government does not need this ability,"

Extremely debatable, given the fact that every nation on planet earth basically uses monetary policy.

A rational policy whereby currency is exchanged for other assets at a rate using benchmarks is preferable to a strict currency.

A better economic policy might even allow almost anyone to exchange assets for currency. Then the market can decide how much is in circulation (though arguably that is already happening, just the levers are in the hands of a body, not a distributed group).