My issue with the dp-review of the 6d2 is that they didn't really try to get great pictures from it, rather, it seemed like they zeroed in on the weaknesses (low-iso DR and ovf tracking), and built the review around that. In fact, the first preview article of the 6d2 was them complaining about the sensor. Other statements in their review also shows they just didn't try, like this:
"We've also had some issues with outright focus accuracy when using the viewfinder, so for formal portraits or perhaps paid event coverage, it's best to switch into live view just to be safe."
So did they even bother to micro adjust? Doesn't seem like it, which also brings into question how accurate their af assessment was. With proper micro-adjustment, af is very accurate for me, both with the 80d and 5d4 (ai-servo is not that accurate with 3rd party lenses, but that's not really Canon's fault). They criticize ovf tracking, again not a Canon strength, most if not all Canon sport shooters I know select one point focus and ai-servo - how accurate was this method? Did they even try? It is not that hard to move the camera with one focus point and ai-servo, it really isn't, with the advantage that you get to select exactly what's in focus and not rely on the camera to hopefully select the right focus points.
Speaking of ovf af, which lenses did they use for ai-servo? We know lenses make a huge difference in ai-servo performance, especially within the large Canon ecosystem. It's almost comical they're using old and cheap 50 1.8 and 28 2.8 primes (yes I know they used a few L lenses), while using nothing but expensive G-master lenses for their Sony a9 review. That's fair. (of course they needed to do that, that's the only way to take advantage of the a9's 20fps).
No mention of AWB-W. No mention of anti-flicker. If they did mention it, I must have missed it among the overwhelming negativity. Before posting that you disagree that they didn't try much, please, take a look at their 6d2 gallery. Take at look at the effort they put in composition, settings, lighting, and post-processing. It is almost non-existent. I could have taken better pictures with an iPhone. That's not a knock on the 6d2. You could take terrible pictures with an a9. Point is, in dpreview's eyes, the 6d2 was doa, and for me at least, it clearly shows in their half-hearted review.