At best, it'd be a drawn out Afghanistan with a diplomatic sanction frenzy worldwide. China would be painted by global media outlets as evil if they took a total war approach. They'd have to do it like Russia with Crimea or Milosevic in Yugoslavia with paramilitary groups. Everyday the Taiwanese identify less Chinese making it that much harder.
The only thing that will make them do it is if the US and EU are in a weak state and can't be bothered with policing that. Like another depression and global war elsewhere.
If that were the case then neither would they be reigning in Japan, Vietnam, the Philippines, South Korea, and India. All Chinese strategic adversaries right on their doorstep. India alone could shut down oil shipments to China that all have to sail close by. Japan’s navy is stronger than China’s and they have formidable air defenses. China might just spark a regional war which they probably wouldn’t win. I hope they’re not suicidal enough to test this though.
They don’t care about the people there one bit.
When they control most of the world in the future, they can just rewrite history and nobody will know. Classic move.
Cook didn’t take Trump as a threat enough to justify diversifying his supply chain much, he isn’t losing any sleep about Taiwans upcoming annex.