>Apple would pay Intel to fab their SOCs.

Why would Intel agree to that? Have they ever fabbed any other companies design?

Yes: https://www.intel.com/content/www/us/en/foundry/overview.htm...

There were rumours going around about its demise a few years ago, but a fair bit of that was simply their failure to ship 10nm parts on schedule AFAIK. They're still doing some degree of third-party manufacturing, and I don't doubt once they reach a point of having the capacity for their first-party products on 10nm we might seem them expand.

However, the inevitable flip-side of this is unlike TSMC/SS where Apple can bid the highest for the early production of a new node, Intel are highly likely to keep the new node for themselves to start with.

Apple said they’ve produced 2 billion A-series SoCs in ten years. Would Intel turn down a slice of that very large pie if offered?

Intel currently doesn't have enough capacity to make their own chips and are rumored to be outsourcing to Global Foundries as a result ( https://wccftech.com/rumor-intel-moving-select-cpus-to-globa... - huge grain of salt on this one ofc, but the supply constraints on Intel's fabs are well known - they mentioned it even at their earnings call) - why would they stop making their own products to make Apple's instead? Apple'd have to pay an absurd amount for that to make sense.

Apple has an absurd amount of money.

Even if TSMC slipped a year it would still be on par with Intel 5nm so Apple would still be better off