None of those are ISA (https://en.wikipedia.org/wiki/Instruction_set_architecture https://en.wikipedia.org/wiki/Instruction_set_architecture) issues - they are

None of those are ISA (https://en.wikipedia.org/wiki/Instruction_set_architecture https://en.wikipedia.org/wiki/Instruction_set_architecture) issues - they are firmware/os/SoC issues. The other issue is manufacturing process - AMD is getting to 5nm only recently and the results in lower power consumption are already telling. IOW ARM doesn't have some magical ISA level stuff to do more stuff with less power or avoid doing stuff entirely that x86 couldn't replicate.