Those chips were designed and fabbed by Intel, not by Apple/TSMC respectively. That’s the relevant difference, not the instruction set.
The instruction set has only moderate impact on the chip’s frontend, and no impact on the backend. Most design decisions are unconstrained by the choice of instruction set.
The instruction set has only moderate impact on the chip’s frontend, and no impact on the backend. Most design decisions are unconstrained by the choice of instruction set.