Yes. but I also think that having high bitrate for 10bit 422 will account for the missing information in color, comparing to 444. But all of this circles back to the use case: are you filming a talking head or in a forest with lots of trees and moving micro elements that take up the bitrate so even thou the files are large it's justified as the utilization is high.
But just like Andrew said in the original post: "- ProRes 422 HQ in GH6 and Nikon Z9 is too big, not practical in my opinion - may as well shoot raw?"
Go watch DpReview's episodes and ProAV TV. Their shows might as well be audio only except the actual image comparisons.