I always wonder if this is a possibility. They've worked so closely with TSMC that they've many times over the decade bankrolled R&D and equipment that TSMC uses. I would be super interested to know if that relationship has left them enough know-how of the fab process to someday control their destiny there, that would actually be pretty insane.

Apple almost certainly has entire production lines at TSMC that they effectively own. I don’t really think bringing chip fabrication in-house has any immediate benefit for them.

We can observe with Apple’s pricing staying stable that they have some of the best supplier arrangements in the industry.