Gold is being picked up by China simply because you do not hold Treasuries of those you are going to war with. This is the situation with China and the US.

As for the USD, it is a joke to think it is going anywhere. People really do not understand how things work.

The US is by far, the largest consumption economy that the world wants to access. If they set up another currency, they introduce FY risk. This means their trade success becomes dependent upon the USD.