If you remove non-industrial and financial activity from US GDP, the economic picture is bleak. US and G7 have been steadily deindustrializing while BRICS have been doing the opposite.
US GDP is misleading in the sense that it increasingly includes a large portion of economic activity that isn't actually producing tangible wealth.
Comparative advantage only works without trade barriers, and when the USA has something people want to import cheaper than elsewhere. The USA doesn’t have competitive exports. The USA is the largest net importer. By an order of magnitude. The USA is deeply in debt in both nominal financial terms and in real trade terms.
What's the USA's comparative advantage? Nukes and dollars. Demand for dollars and rent seeking via the post WWII global financial system. But G7 is no longer the only game in town. They have become the consumers while the rest of the world has become the producers.
Moreover, the leadership in China is fully aware of the macroeconomic situation and USA leadership doesn’t even appear to know how tariffs work.
You have just described the US top comparative advantage. There is no economy in the world that allows you to create a company, open a bank account and start trading. The UK come close but doesn't completely match the US.
The US is the global engine of the world because it has accepted to be very negative on NIIP. (https://en.wikipedia.org/wiki/Net_international_investment_p...) China or the BRICS or Russia do not offer an alternative and not because of lack of technical capabilities; they just don't want to do it.
China can replace the US dollar "hegemony" in a few years. They keyword is can because they don't want to do it.
It seems to me that NIIP is very related to high US stock prices. Everyone, including Americans, wants to invest in the US. Americans own American assets, and so do foreigners, but Americans don't want to buy foreign assets. Hence the high prices of American stocks, and the NIIP thing.
US GDP is misleading in the sense that it increasingly includes a large portion of economic activity that isn't actually producing tangible wealth.