Of course they have the money, but I don’t think they have the demand from their own products that can keep a fab running full-time through its lifetime. I just don’t see them selling low-end devices or producing low-end devices for others.
That would make owning a fab for themselves uneconomical.
Exception would be if they managed to build a fab that’s better than what others have, but I don’t see them do that, either.
On the other hand, TSMC, without Apple’s money, might not be as strong as it is with it, allowing Apple to beat it, and have the best fab.