I think It’s going to be ok. Rome, Britain and France lost their empires when their currencies collapsed, but the US doesn’t have far flung holdings, maybe the military will be weaker, things will be more expensive and the US will dominate less but it could bring more balance to the world.

Americans will have smaller vacations, smaller homes, smaller appetites for hobbies, smaller cars, lower standard of living maybe but America can adapt and maintain a high standard of living by cutting out waste. Less selection at the grocery, less wasteful transportation choices, less wasteful energy practices, more efficient lifestyles.