Lets not forget that the 80D -that I bought as a fall back cam- has 9 cross type AF points sensitive enough to work at f=8. It allows even for tracking birds with my 100-400mm mkII and the 1.4x extender installed.
I found that and still find it an great improvement over my 7D mk II. And thanks to the touch screen, I haven't missed the joy stick for one second.
Apart from that the performance of the 24 mp sensor-chip isn't bad eighter!
It turns out that I use the 80D more than the 7D mkII, these days. But I agree, a 7D mk III or any other seriuous APS-C cam is way, way overdue.
In the case of the 200-400 mm with 1.4TC you are right: then you simply need the f/8 AF-points for the combo to just work.
But for the rest my experiences are quite different. I also have both the 80D and the 7D Mk II.
With the 100-400 II, the AF on the 7D Mk II is faster and more reliable than on the 80D when fast moving aircraft and birds are concerned. The same goes for the 500 mm II.
Only when subjects do not move fast and/or eratically, will the difference between the 2 be less noticeable or even absent.
That is why in for fast action I always take the 7D Mk II - and have the 80D as a backup or have it ready with e.g. the 15-85 or the 70-200 on it (because the 80D is certainly noy completely useless for action photography).
And when I have to be quick (for instance during an airshow when planes come from the left and a moment later from the right), the "joy stick" is sooooo much quicker: no need to take your eye from the viewfinder, just toggle it and keep shooting.
Also here, it only matters wwith fast action and quick changing circumstances. No need for this when shooting a toddler crawling around.