My guess is it's just the way the companies have headed due to their main products.

Apple mainly deals in their phones and tablets while still making some computers on the side so naturally they'd want to invest more into their mobile platforms where cooling is passive. Thermal and power efficiency is the primary focus while trying to bump up speed at the same time.

Intel on the other hand deals with systems that have cooling systems. Servers and desktop coolers get pretty beefy so can handle a lot. Raw performance wins and thermals are slightly less important. Sure they have CPU's for laptops and NUCs which lack good cooling but those tend to get lower specced CPU's.

I built my new PC last week and saw that the trend in CPU's has done a 180. My first PC was from 2013 and buying an unlocked CPU to overclock for better performance was the norm. Power pull and thermals be damned.

These days the unlocked CPU's boost themselves to a pre set limit but pull big power and generate heaps of heat. Now some people undervolt to try keep thermals under control without sacrificing too much performance.