Whether the US should be involved or not is a valid question: moral, practical, diplomatic. A very recent parallel is that of the war in Ukraine: should the US be involved and be isolationist, or not? I for one think that a more than fair case can be made that holding the moral high ground will also, coincidentally, lead to more stability and more economic rewards. So it's a no-brainer and I don't share your isolationist view.
You should, incidentally, remember that US support for Taiwan goes back to a time when Taiwan didn't even have a semiconductor industry. It's unclear that US support would cease entirely if the US was fully independent in that industry, and it's also unclear whether that will happen in any short-term horizon, or at all.