I am extremely dubious. There are an estimated 10 billion dollars in US bills in circulation outside of the USA. Right now, I could find someone to take a US 100 in pretty much any country in South America, Africa, or Asia. And I cant imagine finding someone to take a Chinese gold backed digital currency in any of those places.
Crypto currencies are playthings and speculative games for a tiny percentage of the world's wealthy- nowhere does any serious amount of actual business, buying and selling of things, use crypto currencies.
And the numbers I find are that 20% of the US dollars were printed last year.
Again, if I buy a house in Argentina, nobody who I buy it from could give the slightest care as to how many of them were printed in 2020. It is a reliable currency, globally, completely independent of US economics.
In reality, Gold is only good for a few things- some electrical uses, and jewelry.
It has value because we all agree it does.
And thats the same thing with US hundred dollar bills.
There are no guarantees for ANYTHING.
EVER.
Certainly, there are exchange rates for the dollar, which people use when exchanging US cash outside of the US. But many things are priced based on local economies- like houses in Buenos Aires. The price of a house in BA, in dollars, does not float with the exchange rate- it responds to local conditions. The dollar is the medium of exchange, because its negotiable, not because of its value in forex markets. Although I do not buy and sell large quantities of illegal cigarettes, guns, or drugs, my guess would be that the price is the price, in dollars, and todays London exchange rate doesnt mean that a kilo of coke goes up and down in rural columbia based on that number.