You know how much money Apple had to pour into processor R&D to build something competitive with x86? That bet paid off for Apple in the form of the M1 and its successors.

Intel is still profitable so they're covering their own R&D cost and they're still in second place in process technology. TSMC is undoubtedly charging a hefty margin for their cutting edge fab process so the economics might work out for Apple doing its own fabbing.