Sorry I am never going to give Canon a pass on this one. They had press releases like this:
www.canon-europe.com
and I quote
"EOS R5 holds its own as the lead camera in productions" no lead production camera in most productions would have such severe thermal constraints. I agree Canon never said specifically that 8K would be unlimited, and no one believed it would be, but so is 4K120, so is 4K60 which I use nearly all the time for gimbal work, and so is HQ 4K30. So after paying $6K for a new body and lenses the only reliable video frame rate and quality that you can get out of the R5 is the same thing you get out of the EOS R...4K 30 and written to a single card.
All Canon had to do was make an R6H version like Panasonic did, make it bigger, add a fan, give it backup video recording capabilities, and remove the recording time limit. That would have been the perfect camera.