There is a constant and increasing demand of US Dollars on a global scale. Constant because oil is traded in US Dollars, increasing, because if the global economy gets stronger and the demand of oil increases the demand for US dollar increases.

That goes back to a deal our great nation did with Arab states, into which we installed puppets. We protect them, they sell oil for US dollars.

Now, when the demand for oil decreases, because over a billion cars, trucks and other oil consuming machines will be replaced by electric machines, the demand for US dollars might decrease too. There is a number of US dollars circling around the oil trade, if that trade comes to an halt, the dollars are still there, but the merchants have no need for the money, since sustainable energy makes countries less dependent on oil trade. I highly doubt that the US can impose similar deals to force countries to use US dollars for their regenerative energy supply.

If the ciculating dollars aren't used to trade other products, holders of US dollars might sell US dollars for other currencies, to trade in currencies needed. For EU products in Euros, Renmimbi to buy Chinese products and so on.

The result is that the US dollar comes under pressure. The US would have to sell so much more products to outside the US in US dollars, that the 'new' trade substitutes the loss of trade in petro-dollars.

If that's not the case, the US dollar will fall very low compared to other currencies in the world. Which, on the one hand would make US products, such as Teslas cheaper to export, on the other hand US companies are so much cheaper to buy. For instance, if 1 USD is 2 Euro, then USD 5bn Tesla market share is only 2.5 bn €.

At the end, a US dollars with a low value, not because the economy is weak, but because there are too many US dollars available no one wants, makes our great nation vulnerable for foreign takeovers of our great companies.