The US has a huge internal market, with free interstate trade and no need for localization.
The US has accumulated colossal scientific and R&D resources, which regularly produce industrial breakthroughs. Lower taxes help, too. (Lower taxes is what a country can afford for general benefit, not a sloppy pro-rich policy.)
But most importantly, USD is effectively the world's reserve currency, so the US can literally print money, and much of the rest of the world would gladly take it; it's like gold, only buttressed by the US's economic and military might.
The UK has none of these advantages. The British Empire had some of these, but it's gone. Another large factor is that the US emerged from WWII relatively unscathed, while Britain was badly hit, and could not grow as fast.
You know, if you put it this way, it's really a miracle that britain as an independent country still exists at all, that it's not been conquered from the continent since 1066, and that has been in no small part thanks to a british foreign policy of making sure that no country in europe becomes so dominant that they might take on britain, a foreign policy which included that security guarantee to Poland.
The US has accumulated colossal scientific and R&D resources, which regularly produce industrial breakthroughs. Lower taxes help, too. (Lower taxes is what a country can afford for general benefit, not a sloppy pro-rich policy.)
But most importantly, USD is effectively the world's reserve currency, so the US can literally print money, and much of the rest of the world would gladly take it; it's like gold, only buttressed by the US's economic and military might.
The UK has none of these advantages. The British Empire had some of these, but it's gone. Another large factor is that the US emerged from WWII relatively unscathed, while Britain was badly hit, and could not grow as fast.
(Edit: typos.)