Yea the old narrative of "arm is power efficient, but doesn't actually run real desktop level stuff at that power level" is pretty dead at this point.. it now runs desktop level stuff at 3x lower power than intel's latest chips.. and the potential for apple's chips to keep improving at that same power envelope is definitely there.. so...
The ARM ISA are ARM as implemented by a team with decades of low power chip design expertise is possibly not the same thing. There probably is a quantifiably larger (than for raw performance) perf/watt tax with X86, but on the same process I'm not convinced it's all that huge.
Intel were resting on their laurels for way too long. They've risen to the challenge rather than started panic-selling (give up on process), so exciting times are ahead I hope.
