The post makes it clear they’re making heavy use of multitasking and you’re isolating just one task then saying the CPU is overkill. I don’t think simultaneous note taking, Airplay display and remote control of a Mac was a solved problem in 2014.

And I think the broader question is “is this functionality worth $1000 to the person using it”, the answer is yes and the specific grade of CPU inside the machine doesn’t have a ton of bearing on that.