It doesn't matter. They were only proposing this for trade with China, and the USD is useful regardless. Notice how nobody in Europe is worried that the Euro is

It doesn't matter. They were only proposing this for trade with China, and the USD is useful regardless. Notice how nobody in Europe is worried that the Euro isn't the primary trading currency for oil, and the Euro is worth more than the USD? The only existential threat to the USD is an actual civil war in the United States. I don't even view cryptocurrency as a threat.