When one controls the OS and much of the delivery chain, it is not unthinkable to decide to through some billions of $$$ to create a chop optimized to serve exactly your needs.

So this is precisely what Apple did, and we can argue it was long time in the making. The funny part is that nobody expected x86 to make way for ARM chips, but perhaps this was a corporate bias stemming from Intel marketing, which they are arguably very good at.