Another thing folks aren't discussing here is that cartridges with more danger space than a "good" QD gun would give are going to be high recoiling and/or have very limited barrel life and/or very restrictive barrel heating.
Any really fast 7 or 6.5 with high BC bullets kicks way too much for 98% of shooters to shoot well over and over again. Muzzle brakes mitigate this only on the surface, and make other aspects of shooting and communicating much harder (vs suppressors, which typically mean lower recoil cartridges).
A 6UM burns a barrel in under 1k rds, which I don't care about from a cost perspective, but from a simple reliability/usability perspective. You might be on shot 600 shooting fine and see the gun absolutely shit itself and throw grape shot groups by round 650. Next barrel might be good to 750 but you aren't sure and don't want to have it go out during a hunt, so you pull it at 600 just to be safe. At those round counts I would be doing a barrel every year or maybe every other year, which is simply too much hassle for me to tolerate. Or, I leave it alone and don't shoot it much - which to me is also unacceptable. I want to practice consistently with all my guns, since they are all different and require different input to shoot correctly.
22CM or some other fast 22 might literally be the only cartridge too good for QD that maximizes danger space and doesn't have any other horrendous drawbacks. Though barrel life is right on the line.