> pay 30% more taxes

This is scaremongering - taxes are in no way 30% higher in EU.

Someone pulling mid-6-figures in the Valley is already paying a ~35% effective tax rate (state + medicare + federal). That same person taking a low-6-figures job in Spain would pay ~40% effective tax rate - and Beckam's Law would likely cut that to 24% for the first 6 years in any case