This makes the very incorrect assumption that you could just swap out the TSMC staff and things would continue working. Chip fabrication isn't just about pushing a button to turn on a machine. It requires the massive amounts of esoteric knowledge of all the processes, machines, chip design rules, everything.
Why the assumption that Taiwan would choose death rather than give up their fabs to the Chinese?
I have seen this implicit assumption here a lot, but I just don’t get it.
Why would they smash hundreds of billions of dollars of investment for freedom from the Chinese yoke, if they have to choose between the fabs or lots of people dying?
MAD, or at least MAW (mutually assured wounding). Taiwan wants China to know that a hostile takeover will cost China TSMC[0] thereby disincentivizing China from taking over Taiwan. To say 'we value our people over our fabs, please show mercy' just makes them all the more likely to be taken over.
[0]including associated international outrage over losing their chip supply.
Plus the premise I think is weird. If China is going for TSMC that in itself is already full blown war.
Because that's what war is?
Do you imagine America would let itself get invaded, because their trillion-dollar jet fighter program is too expensive to let people shoot at them?
For the other replies to you saying that they can't just use the machines, China has been and likely still is trying to poach semiconductor expertise from Taiwan. One thing they lack is EUV lithography machines. I'm not sure if they ever got to purchase any, but the US government has blocked ASML from selling any to China.