Because their cost of living is insane, the social safety net is shitty, labor protections nonexistent, and they don't get any holidays, among other factors

Almost none of this is true.

Labor protections are indeed less, but this is actually a good thing. Like with many free-market topics, "labor protections" are a very dangerous thing, because they are a policy that sounds extremely good to the voting public, but many economists can tell you it's actually bad. US just got lucky, that it tricked the public to vote against it.

The pay difference is not a factor 2. You are paid 300-400% more than in the EU easily in the US, and the difference grows if you compare net pay vs before-tax. Cost of living bay area vs center Paris is a wash. Hell, I'd say the food is actually cheaper in the US. Frankly, unless you know your way around to avoid tourist places, food is cheaper and better in the US compared to center of Paris, although I'll agree that if you look around you can find much better in Paris than in the Bay Area.

And if you're employed, especially as a SWE, medical care is better in the US. If you're not ... EU >>> US.