Gold - against which the USD moved in lockstep until the US left the Gold Standart

That's because the Bretton Woods system set the price of gold to $35 per troy ounce. It would be dumb to pay more than $35 per ounce on the market because you could just exchange $35 for an ounce of gold from the government.

Gold is just massively inflated compared to the USD because people do not understand the benefit of fiat currency.

I find it hard to believe that people actually think gold is less volatile than the USD when it has inflated in "value" by 12,516.60% in the last 50 years. If you don't think that the vast majority of that increase isn't due to over speculation then I have a bridge to sell you.