[KaiserPro]

I think we need to move away from thinking of money as a store of wealth, but a indication of value. (wealth is a side effect, it will of course always be a store of wealth.)

Pegging currency to gold or silver gives it the illusion of being of a fixed value, that can't be gamed or changed. However history says otherwise. Its continuously mined, and there are industrial uses so Gold and silver's actual value will still fluctuate.

plus whilst tradeable gold is normally stored in vaults, there is still a boat load of "free" gold that can move around and cause monetary problems. Its a side plot of one of the James Bond books.

You also have to remember that even if there is a physical backed standard, banks still need to lend, which means that in practice it'll still be a fiat currency, just not centrally controlled.