Well this was a polite and informative debate!
I see now that in a handful of CPU intensive titles, the i7 can offer some gains- although I'm stopping short of agreeing that the difference is huge for most of them- usually <10 fps... i7X excluded. And it cannot be ignored that in certain games, HT actually hurts performance; that deserves to be factored into the overall picture. Yes, HT can be turned off, but that requires going into BIOS every time you want to game. Kind of a pain...
Yes- the Overwatch graph you posted does show an impressive 42 fps lead over the i5- but at 200+ fps for each CPU, it's a stat only and not really relevant. Now if that 42 fps lead was say, 120 fps vs 78 that would be much more significant.
I'll also reaffirm my feelings that the i7-3960X should be excluded here; it's a 6 core, $1100 CPU that share's little with the "regular" i7. You know- there's the Mustang and then there's the Shelby Cobra Mustang. Two different animals with (confusingly) similar names.
That being said, I will consider an i7 for my next build in 2018... not only for gaming, but for faster loading of web pages, multitasking, etc.