> (but keep in mind, the value of a currency is dependent on a lot of factors, and not just the gold that is backing it. Otherwise currencies backed by nothing would all be worth nothing, which we know isn't true).

True, but once you've pegged the currency to gold, it can't fluctuate very far from the price of gold. A change in one is necessarily an equal change in the other. Currency that isn't backed by gold is free to fluctuate independently of the gold price, but gold-backed currency isn't.

You could have a currency backed by a weighted basket of commodities, but that would be "backed by a weighted basket of commodities", not "backed by gold, but the backing is metaphysically different than you might expect".