Actually, I did use LV with dual pixel AF e.g. of my 7DII in (not very frequent) cases when I had my old EF 500mm f/4.5 attached with a 2x TC, because the AF sensor then stopped working @ f = 9.0. But of course that was always on a tripod. Btw AF was quite slow back then with this particular combo, so it was only useable for quite steady settings.
The 5D series did start to take off as very good action tool with the 5D3, with which I had a surprisingly high in-focus hit rate with birds in flight (with an old club of an EF 500mm f/4.5 lens). This particular camera kept me with Canon, I loved it, despite its shortcomings (not the biggest DR and critical shadow noise).
Do you know Ming Thein's great review of that camera that he postet in 2015? As a Nikon photographer he was particularly floored by the fact that a digital camera can produce pleasant colors just out of the box. Based on my wife's extended Nikon gear, I immediately understood what he meant. My wife was extremely frustrated by Nikon's color rendition back then, but when anyone tried to address that problem in Nikon forums he ended up in a better knower's shizzle storm. You still can read Ming Thein's highly influential blog that started the internet fame of Canon's really great color science (= satisfying results in many settings w/o massive post-editing):
blog.mingthein.com
I disagree: for tele lens birding/wildlife photography the R7 is within Canon's current eco system still the camera that provides the highest resolution in the center of an image, and that allows for more "reach" (if there is enough light available so noise doesn't kick in too much). With the same pixel pitch, a FF camera would have about 80 MP. Wildlife photography is of course a special branch of photography, but I guess most buyers of the R7 do use it for tele photography and possess also a FF camera for other settings (like me). So, I am overall happy with my R7 for that purpose, despite its shortcomings. Okay, if Canon would come up with an 80 MP FF camera, then one could activate the crop mode in typical birding settings. Such a camera would maybe kill the high res APS line. But the question whether an 80-100 MP FF camera really makes sense in real life photography, was discussed here already extensively - I don't want to open THAT can of worms.
Yepp, that's for me more a "minus" than a "plus", despite the fact that I don't care much about RF-S lenses. But this may also be a hint that Canon realized at least that R7 users have also FF cameras anyway.
Back in 2015 in Cyprus, I took a live-view shot of the moon hand holding a 7Dii with a 300mm f/2.8 ii with a Canon 2xTC + 3rd party 3xTC at 1800mm - but I did rest the lens on a tree branch!
I like to think even with an 80+ MP FF R5 - style camera (which would probably cost 5-6 K Euro, Dollar, Pounds) there could be a place for APS-c sports- and wildlife-capable cameras, for instance for new or young photographers and as backup to the high MP camera. If the rumours of 39-40MP R7 II are true (who knows nowadays...) one would need 100 MP FF for the same pixel density in an APS-c crop. Even a 2.5 K$ R7II would be more in the price bracket of an R6 line model which sells more units than the higher end R5 line models.
