Fair point. Mainly I agree with the sibling comment: the revealed preference of many people around the world, including many people from the richest countries in Europe, is to move the United States and then settle permanently. I think that means a lot.

Obviously you can also say that the US is geopolitically successful because of its global military and diplomatic dominance, but I account zero value to this.

At a minimum, it's been a place that people wanted to come to, more than they wanted to come to anywhere else in the world. That's successful as measured by people.

(Or at least, people wanted to come until the last couple of years...)

Nobel prizes? Manned moon landings? Reserve currencies? AC units per capita?