Up to now, my 4770K @4.2GHz seems to be doing okay with games I play on it, though I'm limited by my GTX1080 at 4K (reduced ingame settings). Still, can't complain about my gaming experience given my hardware constraints. I don't, however, think of this rig as a gaming rig as it handles my HTPC requirement....
I also have a 3960X which, though slower than the 4770K in benchmarks, I have more faith in due to its 6C/12T, hence it (with my GB RX VEGA64 Gaming OC) is my 2nd gaming rig. So far, while framerate isn't as high as my 3900X, it's still well into the playable range (on my Samsung 3840x1080 monitor).
With my 12C/24T 3900X, I believe my main rig is capable of handling whatever future games that require >8C/8T (and to some degree, the 6C/12T 3960X as well)......I do need to just upgrade my PowerColor VEGA64 Red Devil to an Ampere or big NAVI.