If any country X annexes any country Y without doing the other stuff, the annexation won't be profitable.
Plus, a significant minority of Taiwanese are actually favorable to China (around 10% of the population). China doesn't want to loot Taiwan. They want control of the island. I still agree with you that it probably wouldn't go well for part of the population as illustrated by the current situation in Hong Kong.
You can read this article from the New Yorker for an actually raisonable coverage of the situation (something which is sorely laking in the US media establishment): https://www.newyorker.com/magazine/2022/11/21/a-dangerous-ga...
There's a big hole in that argument: annexation is not free. It has costs: the destruction of infrastructure assets, loss of life, capital flight, skilled labor flight, private sector boycotts, the burden of new sanctions and the expenditure of military action, occupation and administration.
The only reason to annex a country is if the expected gains offset these costs. Therefore, looting.
*This is what I mean by looting.
It is flexing right now because one, there might be a window of opportunity as the US is modernising its navy, two, it’s a way to keep Taiwan under the current status quo at time when American diplomacy has stepped up its own aggressive posturing towards China, three, it’s useful for Xi internally.
China is not trying to redirect Taiwan output to the mainland. As I said, Taiwan is right next door and already has a mostly integrated economy. They want to fold the island into China proper.
Taiwan is not and never was an economic annexion for China. That’s not the point. If you start from there, you are doomed to be wrong.