The semiconductors are propping up the AI zietgeist in the US, but is that true globally? Why would Canada/Brazil/Europe care about Taiwan? China will still sell them the chips.
The only one who would really care is the US. So by taking Taiwan, China blows up the US stock market and takes control of the chips.
Every country on Earth benefits from the chips that come from Taiwan, and not just the governments, the people using pretty much anything that does computation. That includes China.