It might be rare, but right now those engineers are super valuable, and are getting paid for it.
demand and supply.
you see the same thing happen with self driving engineers commanding million dollar packages because they were in such high demand and supply was so low.
They are super valuable now but their value will decrease as the Chinese semiconductor industry catches up, so it's not like TSMC will have to pay 2x the salary forever. However I know many people (not at TSMC) who would take a lower salary to work on green field projects.
demand and supply.
you see the same thing happen with self driving engineers commanding million dollar packages because they were in such high demand and supply was so low.