Is it overkill? I use all 32 of my CPU cores when building C++ or Go, and while fuzz testing. I'd take 64 if I could get them. There is no reason why I'd ever want fewer cores, even if it doesn't make Chrome or Emacs any faster. Latency is crucial during the edit/compile/debug cycle; making compile as close to 0 as possible is always a productivity win.

Finally if you think Intel power saving is bad, wait until you see AMD's. My Threadripper system idles at 270W. This is exceedingly wasteful. Before upgrading to a Threadripper I had an i7-6950X which idled under 100W. The difference is quite noticeable.