Taiwan isn't Ukraine. I suspect the US will not take the prospects of having a substantial Chinese military presence on Taiwan so lightly, seeing that it puts them 100 miles closer to the Marianas islands chain, and such a move would freak key US Pacific allies like Japan, the Republic of Korea, and the Philippines.

Anyway, this is a theoretical discussion as I don't believe China will take the monumental risk of invading Taiwan now, when it has the option of drawing Taiwan in culturally and economically over a gradual period. Already, between half a million to a million Taiwanese live and work in China (numbers are probably depressed now because of Covid).