>where efficiency is of no concern and all you want is performance

That is not strictly true. If you allow 10W per core ( The A16 CPU Core @ 3.5Ghz only uses ~5W max in case anyone is wondering ), even a 32 Core CPU puts you at 320W. That is excluding Memory controller and I/O. Worth remember Apple's CPU is single thread only. Compared to AMD / Intel x86 counterparts which has 2 thread per Core. So once you factor in multithread usage, which is what most of the performance difference are coming from on desktop. It still matters.

There is a difference argument if you have a need of 300W CPU and 500W GPU though.