MAC/Apple did not start it. IBM started it with their IBM 801 in 1980. Or Sun UltraSPARC servers, or IBM PowerPC chips. I would argue that the cell phone industry "started it" to a degree that brought it to everyone's hands... and I'm talking predating the iPhone.
We'll see if it is all going to ARM. While ARM is popular right now, it's generally a lesser performing package with lower power requirements, while x86/x64 is the higher performing and higher wattage. For a desktop/workstation, x64 is still king in most respects - and seeing, as you pointed out, that Intel and AMD are working on big.LITTLE designs for themselves, the x64 architecture could easily compete on the "power" side of things (at least I predict that could be an outcome) if they can get it to market and compete, etc.
The 1996 movie, Mission Impossible references a "686 prototype with the artificial intelligence risc chip" -
https://getyarn.io/yarn-clip/97eb193f-4bc2-481a-ae17-ae24cff48a32
Point being, ARM RISC isn't anything new and it's been a long road for ARM to bring "competitive" to the consumer computing market... only realizing it's "limited" successes so far due to mobile devices and power efficiency requirements... and there is nothing wrong with that.
People often fail to realize that ARM RISC is "Reduced Instruction Set" - which is not necessarily desired, nor performance focused when compared to CISC - "Complex Instruction Set".
The other main negative for RISC is that it can only execute one instruction per clock, whereas CISC can execute many instructions per clock - and many times that's where CISC wins over in the performance department.
So, it'll be interesting to see what happens with ARM overall, however, I think this could play out in a way in where ARM forces Intel/AMD x86/x64 processors to compete on the power requirements areas... and if they do, well, "goodbye" ARM. If they don't, we very well may see the shift you speak about.
It's all very "up in the air" right now.
