One difference from here than other developed countries is that America has a lot of rich people. Not just super rich that you hear about on the news, but tons of millionaires. The software salaries at FAANG are true, but basically every industry has a cream at the top that makes absurd money compared to what they would make in other countries. Doctors, dentists, lawyers, military contractors, salesmen, stock traders, fast food franchisees - every state in the US has a sizable pool of millionaires. And while the tax rates that someone making $800k salary vs. $80k salary aren’t hugely different, 37% of $800k is a hell of a lot more total than 30% of $80k. And that’s where the bulk of the taxes are made - not from the poor, or the middle class, or even the super rich that often game everything, but the upper middle class / “normal” rich.