Those same people would be making $250-300K in the US, with about 25-30% effective tax rate (depending on the state), and healthcare mostly paid for by the employer. Assuming they're actually senior and get paid that much in Eastern Europe.

I'm not sure they would. $60k is just typical salary for someone with 5-10 years of experience in ex. corporate Java. They are not stars by any strech of imagination, just solid performers.

Outstanding people make $120-160k - and here I agree, they would probably make twice that much if not more at FAANG in SV. But, their taxes would be at 35-40%, and housing would also be more expensive. I've often considered moving to SV (I'm making $160k in Poland). According to my calculations, I would be saving up to 50% more money there, but for me that's not enough to move to the other end of the world - not to mention the gruesome immigration process.