As satisfying as that sounds, the business world comes down to trust and no one does business with a gun to their head. I am almost 100% sure that what the U.S. Politicians are doing is going to significantly impact the competitiveness of and market share of U.S. companies.
The Chinese have a monopoly on processed rare earths and if they want they can cause significant damage, the shortages can get much worse. But they are much smarter than your average American politician, they know that if they use it in a tiny dispute it will ultimately affect their companies, so they leave it as a weapon of last resort, like a nuclear bomb.
The best strategy used to stagnate the Chinese semiconductor industry has not been export controls alone, but has been to make Chinese companies addicted to equipment, software, and technology from the United States and foreign in general stalling local competition. That is why export controls are lowered each time their capacities increase. The Neocons have such a low IQ that they haven't even realized it yet. Even though he has been in front of them the whole time. Without that, it is true that they would not be making 7nm chips, but the ecosystem would be a lot stronger.