I'm not opposed to having more MP, but it's not a major decision driver for me. I prefer integrated grip bodies for ergonomics, which I why the 1D X remained my primary camera until the R3 came out, even though I had the EOS R. With current Canon bodies, AF performance is no longer a big differentiator (yes, the R3 has a slight edge over the others for fast action but the differential is nowhere near what it was a few years ago). I'm quite happy with the 24 MP sensors in my R3 and R8.
I crept up the ladder to 50MP when I got my 5DSR, but found the images too noisy at ISO 1600, the burst speed was very slow, and storage and processing times were an issue. Later I dropped down to the 30MP of the 5DMkiv which produced nicer images. At the time I considered 30MP to be the "sweet spot".
Then I jumped on the MILC bandwagon. I decided to get the R5, which produces nicer images and allows for heavier cropping, which I need for wildlife as I can't afford (or deal with the weight) of big white primes. Noise isn't a problem even at ISO 3200 or 6400, thanks to Topaz. Storage isn't a problem either, as I constantly revisit and cull older shots, which helps to keep storage my needs lowish. It also reminds me of how poor some of my early shots were, thereby encouraging me to reach a higher standard overall.
I don't really feel a need for more than the 45MP of the R5, but having got used to it, I wouldn't want to drop down to 30 or 24MP again, although I completely understand the reasons why other folk find it adequate. I can't think of any reason why I'd pay $5K or more for a "R5s" or "R5ii", let alone an "R1". The R5 ain't perfect, but it would take one hell of a camera to get me to upgrade.