I understand that. But that wasn't the point. Historically laptop and desktop PC CPUs have been different because of the different requirement - laptop's priori

I understand that. But that wasn't the point. Historically laptop and desktop PC CPUs have been different because of the different requirement - laptop's prioritise efficiency whereas desktop pc users prioritise performance. Apple instead has used the same CPU on their tablet, laptop and Desktop PC. (And note that even Intel / AMD processors do the kind of power scaling that you described without any specialised low power cores - all cores are designed to run at varying speed. Thus, when a small task is executing, the core executing it runs it at the minimum acceptable speed and saves power. But the same core can run at full speed on demand. That's a more acceptable tradeoff for me for Desktop PCs, especially considering that ARM CPUs already are very efficient.)