If one has the money to carry two RF bodies, then it's very practical. See my comment previously about dust. Amateur or pro, carrying two D-RFs would be better than one if only for the reason of keeping the sensor clean.
For me personally, I beat the crap out of my gear. Have carried 2 Ms and a DSLR into combat alongside a full 782 load with rifle. Of course, I was employed to do that. So, even three cameras is not overkill or ego or whatnot when the job needs to get done.
One wide, one short tele and you'll get the shot. If you change lenses, you'll miss the shot and sometimes (depending upon where you are posted) you may get shot.
And if people like carrying two cameras or twelve cameras, who cares?
Have fun folks!
Phil Forrest