The US has more supply, not less. But the demand is even higher. Supply and demand around industry verticals in geographic hubs like SV doesn't follow simplist

The US has more supply, not less. But the demand is even higher. Supply and demand around industry verticals in geographic hubs like SV doesn't follow simplistic supply & demand laws. More labour means more fuel for starting fires, and lots of fires require more fuel to grow, throwing off more and more heat (profit); meanwhile, if you're in a fuel-scarce region, to pursue the metaphor, it may not be possible to start a fire at all. Salaries are high because the companies have global scale and are competing with other companies with global scale, but they can only be global scale because they have lots of labour supply, and they only have that because they're co-located and can utilize fungibility in the labour market. There's little need for data scientists in small local companies.