Argument is that USA borrowing is contingent on foreign superpowers buying US Treasury Bonds, which they "started to stop" doing a couple years ago
> So much of the infrastructure just operates using dollars but nothing is stopping anyone from not using dollars
Other than pissing off the USA who will manufacture some moral imperative to sanction/proxywar/depose said government
The fact that oil is settled to this day primarily in USD has everything to do with the US and Saudi Arabia. Understanding this system also helps one appreciate the relevance of very contemporary issues like China attempting to push oil producing nations to settle their contracts in yuan. It's not about the short micro level effects, which would essentially just be a currency conversion, but about the macro level effects and implications of what currency the most in demand import in the world is offered in. If China succeeds with their goal, the economic consequences for the US could not be overstated.
I am not sure what blockchain engineers have to do with selling treasury bonds. The larger issue for China is that they have to do something with their dollars. It's not feasible just to dump them.
Unfortunately (or fortunately depending on your perspective) the USAs ability to continue to borrow does not appear to be ending. It is true that so long as others will lend to you in your own reserve currency you can basically just keep borrowing. I didn't think that the US could borrow $20T but maybe we can borrow $50T or even more. It seems for the time being the sky is the limit.