America does fab. However not newest nodes at high capacity. It just doesn't take building an identical factory and hiring away engineers. There is a complete supply chain of specialist companies which produce or fix the part the part that goes into a machine that that ... . Not mentioning that those construction costs are at economies of scale of building factories.

Such a thing can't be build in the US as every state needs a piece of the pie. An US run copy will be more expensive even when you ignore wages. Extra spare capacity for emergencies is not sound either.