Fred, I know you forgot to mention shutter noise, mirror flap. Many times critters have fled or flown away after the “ratta tat tat” of my DSLR. This issue and the Zs IBIS made the switch a no-brainer for wildlife. However, this thread is about the F v Z glass, not the supporting platforms. The FTZ adapters work well for the most part with F mount glass like the 500PF. Older lenses not so much. Most of us can remember how to manual focus on something that isn’t streaking across in front of our cameras. Then maybe we can? I have a 180mm f/2.8 ai-s lens that I’m itching to try with the Z8 on some birds near our feeders. I’m not throwing my F mount glass under the bus to have the latest and greatest offerings. For me there has to be the expectation of tangible improvements over current results.……Those are fantastic coyote shots. But I think there is a false assumption here. People who move from SLR to mirrorless are NOT saying that you cannot get excellent shots with SLR gear. (Maybe you didn't mean to imply that they are saying that, but that is how I read the opening statement). There are reasons to make the switch beyond just getting good pictures (which OF COURSE you can do with F mount or any other SLR system). For some people these are valid reasons to switch and for others they are not. Each individual will have to decide (but just getting good pictures is not the deciding factor, though there may be a few exceptions who think they somehow will magically get better pictures if they switch).
Reasons to go mirrorless:
Lighter weight (helpful if you hike or are older).
Better corner sharpness (important for architecture and some landscape, unimportant for wildlife).
Electronic viewfinder (helpful for low light and for photographing the sun with a telephoto - no risk of eye damage).
Focus points cover entire frame (helpful if you want subject on far left or far right).
In-body-stabilization (works with lens stabilization on telephotos; easier to get sharp handheld shots).