The EU is already investigating Apple as a monopoly. There have been similar vibes from the US. They would see a TSMC purchase as a big monopoly play and squash

The EU is already investigating Apple as a monopoly. There have been similar vibes from the US. They would see a TSMC purchase as a big monopoly play and squash it. The theory is that at a certain point, vertical integration is so extensive that you are keeping all the profits along the entire chain and nobody can compete on price. That's a very bad place for government-enforced monopolies like Apple (standing on the back of government-enforced patent and copyright monopolies).