Intel doesn’t have to build its own fabs. AMD sold its off and is doing fine. Fabless + foundry is an excellent model that lets each side concentrate on its strengths, that works for most companies.

Intel started in an era when you did have to build your own fab. More importantly, even as others were going fabless, Intel continued to use its superiority in manufacturing as an additional advantage over their competition, who had to drop out of the fab business, and against the merchant foundries too.

But now Intel has fallen behind on both sides of the divide. I’m not sure how they will dig out.

Apple doesn't have to build it's own CPU, but often vertical integration gives one a significant advantage.

TSMC is slave to Dutch ASML, whos is the only one on the planet who can make the EUV lithography technology TSMC uses to make the latest chips.

Who manufactures them for Apple?

TSMC

Wouldn't that make Apple even smarter and more efficient?