Obviously you have not used a Sony with the newer Z battery. I get all day on my Sony battery, FF mirrorless. Actively Shoot 1200 shots during a game, with IBS and lens OS running and still have over 50% battery remaining, seriously over 50%. Add a grip and now you have 2 batteries I could shoot for days. This is not an exaggeration, it is reality. I am not a Sony fanboy, I just moved where the technology that meets my needs is. I will always have s soft spot for Canon, my first SLR was a T-50, its where I learned about photography. Kind of why I still come to this site. I want to see what Canon does next.
No, that's true. I played with different Sony A7 models some years ago because I was quite excited about Sony's innovative drive. But I didn't like the ergonomics and the EVFs then - which have massively improved now. I also prefer to shoot stills, not video, otherwise I would have definitely changed to Sony. I am fully aware that the time of digital mirror slappers is nearly over now, and I will not miss them if ML technology is mature enough (including fast electronic shutters). Especially for birding (not my only interest) I simply need a camera with which I can track, with a 500+ mm tele lens, a fast flying bird and get decent in-focus results. Birds are much more a challenge for the AF system than sports, because contrasts and contours are often softer. Until now, a good DSLRs does this job quite well, so I didn't want to change the gear which I know will serve me.
In fact, for me, digital photography is mature when good light-field cameras are available,providing the ability to re-focus and change the depth of field by post-processing, no need for any AF system anymore. But that's still a dream...
My first camera was a Kodak Retina IIIc, already vintage then, got it refurbished some years ago. Later I changed to a Nikon FM-2. Both fully manual cameras trained my skills the hard way