All of the dollars being held around the world will come back to us (US)and further dilute the dollar 's value. The inflation will be like Zimbabwe. No one will take our worthless currency overseas and we don't manufacture anything here.
Though perhaps not the "manufacturing powerhouse" it may have been "back in the day" (though I'm nearly positive it has always lagged behind Europe), the U.S. is the third largest manufacturing nation in the world, after China and the European Union (so, not including Great Britian), and those entities both have much larger populations.
Manufacturing represents 12% of total U.S. GDP (gross domestic product), contributing $2.3 trillion to the economy, and there are certain areas where the U.S. excels, such as airplanes. It is not always easy to source products manufactured in the U.S., electronics especially, but we still make a lot of stuff. I recently purchased Royabi toolboxes made in the USA. Craftsman tools and accessories (once a Sears house brand, now owned by Black and Decker) are often made in the USA. There is still clothing made here (especially socks it seems), but when cotton items are imported the cotton was very likely grown in the U.S. The U.S. is #2 in the world after India for cotton production, but I've read that U.S. cotton is preferred due to its higher quality. The U.S. is the world's third largest producer of wool (after China and #1 Australia, New Zealand and Argentina are #4 and #5 respectively) ... I always prefer natural fibers for my vesture.
I've worked in agriculture my whole life (though now also in funeral service in "semi-retirement"), and the United States is THE absolute world powerhouse for food and fiber production. Over 20% of agricultural products grown need to be exported as we produce WAY more than we can consume. The U.S. mostly produces what is needed for buildings, though some forest products come in from Canada, I consider them "first cousins".
In the grand scheme of things, when a country can feed and house itself (and there are still enough small-town machine shops and forges here to make any needed fasteners and gadgets, I can think of lots of local-to-me sources for that) it can survive. While not meaning to depreciate the skills of "coders" (an occupation two of the forums more prominent posters practice), I've lived over half my 72 years without electronic and digital "services and tools". I'm very capable with using a
physical library card catalog, "old fashion"
handwritten address books, calendars, and to-do lists, or mailing a postcard/envelope.
Bottom line, I don't see the U.S. economy "sinking" anytime soon ... periodic downturns is another issue.
I'll close with these words from William Jennings Bryan's "Cross of Gold" speech at the Democratic National Convention on July 9, 1896, coming from my perspective as an agrarian rural person. At the U.S. presidential election of 1896 Bryan was defeated by William McKinley.
You come to us and tell us that the great cities are in favor of the gold standard. I tell you that the great cities rest upon these broad and fertile prairies. Burn down your cities and leave our farms, and your cities will spring up again as if by magic. But destroy our farms and the grass will grow in the streets of every city in the country.