And at that point they simply... shift the bulk of their operations somewhere that still gives incentives, and maybe just leave a lightly-staffed satellite office in the US.
That's great. They should do that then. They're not providing value to the US economy at that point. They're purely extracting value from it. They should leave.
Of course, in reality, they never actually leave because the vast majority of their profits is from the American economy.
Of course, in reality, they never actually leave because the vast majority of their profits is from the American economy.