It's certainly in Apple (and every company that requires a leading-edge fab)'s interest to try and keep Intel competitive with TSMC and Samsung. 3 companies is already too few for a truly competitive market. And 2 is worse.
I'd argue it's also in everyone's interest to have some redundancy in the chip fabrication supply chain (esp. given the geopolitical situation in Taiwan). It would already be catastrophic if TSMC's production was disrupted for any reason. It would be even more catastrophic if there was no Intel.