Doug Herr Loc: California

Here's how I see the advantages of mirrorless:

Mirrorless hybrid phase-detect/contrast-detect AF is quick and accurate. DSLR's phase detect is quick, or contrast-detect via live view is accurate. Several who have adapted their DSLR lenses to mirrorless have noted that the lenses perform better on mirrorless because of the improved focus accuracy. Bird Eye AF locks AF onto the bird's eye which is where I want it (animals too) and tracks it over the entire image area even when party obscured. I find that mirrorless improves the odds of accurate AF.

Mirrorless manual focus is quick and accurate with magnified view in the viewfinder, easily visible in bright daylight and without reading glasses, improving the odds of accurate focus.

Mirrorless electronic shutter is silent and vibration-free so timid animals stick around for more than the first photo, improving the odds of getting the photo I want. The most recent 'flagship' bodies from Canon, Nikon and Sony have stacked sensors that for all practical purposes eliminate rolling shutter distortion with no blackout during bursts (20+ frames/sec, with AF).

Sensor stabilization combined with lens stabilization and zero mirror shock improve the odds of getting a sharp photo at slower shutter speeds.

Real-time exposure preview along with a live histogram and zebras allows me to see in real time if the highlights re over-exposed, in the viewfinder where it's easy to see in any lighting condition and without reading glasses, improving the odds of keeping highlight detail.

Can a sharp, well-exposed photo be made with either a mirrorless camera or a DSLR? Yes.

Can any of us tell if a particular photo was made with a DSLR or mirrorless camera? Unlikely.

Getting the photo sharp and well exposed, and having enough time with the animal to get several photos? I'd like the odds to be in my favor.

I've been photographing wildlife for a little over 50 years, with photo credits in numerous national and international print publications going back to 1972 when I was using a Nikon FTn. It's not my place to tell anyone what to think or do, but I'm never going to use a DSLR again.