They're talking about an absolute/total sense instead of relative to per-capita situation. If we forget that the US has more people, they are the best at many

They're talking about an absolute/total sense instead of relative to per-capita situation. If we forget that the US has more people, they are the best at many things. Science, GDP, sports, and so on. That's probably what he means when he says "best". It'd be like calling Google or Apple the "best" tech companies even though you can make more money at some small startups. It's true in some sense (they're the biggest, dominant, etc), not necessarily true in the per-capita sense (I might have a better time somewhere else).