High-wage-high-cost and medium-wage-medium-cost arrangements are on balance pretty similar for the employee. Dramatically higher taxes on the former will push people to the latter. Which, as you note, they can do without even changing employers. There might be some lens through which this is good. Decentralization, or inequality. But tax revenue from this cohort will go down, not up, because there’s so much less income to tax in the first place.