[ac29]

The patents for x86_64 might be expiring soon, but SSE3/4 and AVX1/2/512 are newer. I'd imagine there is a lot of performance critical code written making use of those extensions, and that's just vector stuff. The x86 architecture has added a lot of other new extensions in the past 20 years as well.

[monocasa]

Yeah, but for that, Apple very well might have enough patents in the CPU design space to negotiate a license at this point.