As another commenter rightfully pointed out - you don’t get to be independent and isolationist at the same time.
Indigenous island tribes may have had this luxury for a time, but once your nation is known by another nation, it’s compete or die.
China and various other countries would immediately start filling the power vacuum. Your standard of living would drop immensely and your grandchildren would be consuming Chinese culture within a decade or two at most. The American dollar, America’s total dominance in science/culture/medicine, the spread of the English language - these could all be wiped out fairly quickly if America just threw up its hands and said we were done.
What you’re suggesting would be like Apple saying they’re going to take it easy and just stick with the iPhone 15 for good. The result would be an immediate power grab and some other company would pull ahead, leaving Apple so far behind they’d never catch up again.
