[Followerer]

ARM doesn't sell chips, they sell IP. E.g.: their ISA (instruction set) or soft cores (designs that you can integrate in your own chip and then fabricate).

There's nothing special in the chips themselves, it's the business model what's quite different from Intel's.

Historically, ARM (and their licensees) have designed their cores targeting power efficiency over everything else, but there's nothing that prevents Apple or any other licensee from designing a power hungry ARM CPU.