That is because it is not tied to any currency.
Any commodity based monetary standard requires a certain amount of stability or the economy will start wildly fluctuating since with a commodity based monetary system the government guarantees a certain unit of currency will be traded to a certain amount of that commodity.
There is no stability for investors right now in fiat currency. If you are not into gold, then you have to be in some asset or equity, like real estate or stocks.
In the US, production is down while the money supply is going up. In order to have stability in the economy, its not petrodollars that shore it up, its the amount of productivity the economy generates. That total productivity needs to absorb the excess currency to keep the inflation down. In order to not hyperinflate, your productivity has to rise by the same amount at least of the currency.
That's not happening with COVID and productivity, along with the PMI, being way down. You are producing less but you have more currency. That is the recipe for inflation, as the dollars compete and bid for the restricted supply. Do you think petrodollars is what keeps the food prices in the supermarkets down? No. Do you live in the US? The prices of groceries are going stupid here.
Ironically, it was China that has been exporting deflation to the US in the form of cheap products. Then you put a tariff on them. But even without tariffs, China's production has increasingly turned towards satisfying its own massive and rising middle class, which means it will gradually export less and less. With less goods reaching the US markets and other parts of the world, while the currencies are being massively printed, the currencies are bidding against less and less supply and that drives the prices up.