I'm not saying that total GDP is necessarily the best metric for "richness" of a place, but it is a commonly used one.

I think per-capita GDP is clearly a better metric, putting the US around 10th, but total GDP isn't an awful one for broad strokes.

> So California is 75 times richer than Vermont?

California is also, like, 75 times bigger than Vermont in pretty much every metric, so I'm not sure why you seem so surprised by such an implication.

My point, in case it's not obvious enough, is that GDP is not a good definition of richness in the context of a discussion about how can these things happen "in the richest country in the world".

Except that GDP is a perfectly fine definition for that. A national healthcare system is something which is strongly inflenced by things like economies of scale; measuring by any metric other than GDP and government budget would make very little sense. If the DoD can afford to burn trillions on a jack-of-all-trades fighter that sucks at pretty much all the jobs it's meant to take on, it can almost certainly afford to give every American free healthcare, free college educations, and at least two moon colonies to boot.

The point of the "richest country in the world" remark is that the U.S. could very well afford to be the most progressive modern society if it chose to do so. Instead, it opts to sink money in failed fighter projects and nebulous "terrorist"-hunting surveillance and drone strike programs.