I haven’t read all the comments, but does anyone have a good explanation for why software engineers in the US (especially in the Bay Area, seattle and New York)

I haven’t read all the comments, but does anyone have a good explanation for why software engineers in the US (especially in the Bay Area, seattle and New York) make so much more than anywhere else in the world? Even looking at relatively high cost of living / high services places like Northern Europe it is hard to make the comp work out. E.G. levels.FYI says an E5 at Facebook in London averages lower pay than an E4 in the US.