Its less about the instruction set and more about the specific implementation choices and market they're competing in. Apple has been doing ARM SoC design for a

Its less about the instruction set and more about the specific implementation choices and market they're competing in. Apple has been doing ARM SoC design for a long time and was an early 64-bit adopter, buys tons of bleeding-edge capacity from fabs, and is willing to design in more expensive features like tons of onboard cache that they can make up on margins in other ways because Apple sells complete devices, while Qualcomm etc are mostly in the business of selling chips. So while there are fundamental differences between x86 and ARM, the bigger differences are more "Apple vs other ARM SoC designers" than something fundamentally different about ARM that Apple takes advantage of.