A gold backed currency, rather than a fiat currency, gives control to a physical resource. The ones who control the physical resource and mining dictate the market. It is a very bad idea but probably good for the biggest gold producers in the world, they happen to be China, Russia and Australia (US is #4) [1].

A non-fiat currency is a single point of failure and since it is locked to a physical resource, it will cause many economic downturns with no lever to adjust. If a gold backed petro currency or oil is backed by gold, crypto currencies will explode exponentially.

[1] https://en.wikipedia.org/wiki/List_of_countries_by_gold_prod...