Based on Taiwan Relations Act, U.S. will help Taiwan defend itself. One important reason that Taiwan is strategically important to United States is that it has a very strong semiconductor industry. However, U.S. government has been prioritizing domestic semiconductor manufacturing and research and development in recent years and TSMC also has plans of building new factories overseas, for example in Arizona, United States. This indicates that one day Taiwan's semiconductor industry may no longer be irreplaceable.
This gives rise to a natural question: why should United States care about the defense of Taiwan if not for Taiwan's role in the supply chain of semiconductor industry? Or in others words, is/why is Taiwan still strategically important to United States without its semiconductor industry?
By "strategically important", I am asking from a purely utilitarian point of view.
My question is more from the point of view of United States. I asked a question about this from the point of view of China before.