Say TSMC pays supper competitive US salaries to attract US-only labor, higher labor cost which is causing the end product to be more expensive, which makes that fab uncompetitive globally causing Apple to go buying from someone else and TSMC either choosing leaving the US or going bust eating the losses.
You can't compete with lower-wage countries in a globalized world with no trade barriers and no tariffs, when Apple wants higher profits and consumers want lower prices. Something has to give.
You can put tariffs on imported chips to equalize the field, but then iPhones would be more expensive for the average American and Apple's stock would tank.
So, pick your poison.