I read your post with interest to appreciate your ‘different’ point of view. I am very used to and can fully understand the action sports shooters preferences: a lower resolution camera capable of capturing fast action in all conditions with small(er) files; and fast in camera processing to be able to ship the files quickly. I’m less used to seeing wildlife shooters expressing a preference for a lower resolution flagship camera, even if birds are not their primary pursuit. I should say that I have noticed shooters using their D5s/D6s for wildlife. I’m sure, like your 1DX, these Nikon flagships had the top of the line AF and fps to make them sound choices for wildlife.
My preference for higher resolution cameras – currently a Nikon Z9 – largely reflects my wildlife experience. In Africa, when drivers were not permitted off the roads, e.g., the Ngorongoro Crater in Tanzania, my only opportunity for a cheetah photo turned out postage stamp size, even with an effective 600mm lens. (There were a great mix of photo opportunities in the crater with hyenas and lions also resting in the shade of the rovers). Back home in Texas, many of my wildlife (including birds) opportunities are spur of the moment while documenting other projects, often with no time for hides or walkups. Based on my prevailing experiences, I zeroed in on a goal of carrying 600mm minimum for wildlife, recognizing that I would still be disappointed at times. By now, and with mirrorless freeing us from the f/8 AF barrier, carrying around even longer focal lengths is much more practical – and affordable.
My interest in higher resolution is to be able to crop – quite a bit at times. So my interest in the new Canon models is in the R5 II, although some of the R1 features are tempting, and, if paired with the Canon RF 600mm f4, would probably meet my objectives. I would have to rent the gear to check it out in my environment and make sure I could lift that lens. Btw, I’m seeing very few wildlife reviews of the new Canon models, the R5 II or the R1. Still too early, I think.
After the Z9, I frankly thought that the traditional 24, 20’ish MP flagships would shift to 30’ish MP sensors, but that doesn’t seem to be happening, at least with Canon. I’m pretty sure that processing, transmission and storage measures have improved, making me wonder if 30/40+ sensors are that much of a penalty. But, faster is still faster, I guess.