[davidmanze]

Dunno if that changed with newer models, once they lock on a subject mirrorless camera autofocus is deadly fast and precise, however the system must  first find the subject and lock on it, for sports indoors or car races it's an easy task however for wildlife and birding dunno if mirrorless can lock on a subject as  fast as a pro DSLR

You're joking, right?

As I mentioned a little further back, just look at the R5 image thread on POTN to see how good this camera is at birding ...

   I think Toni is referring to some ML quirks........ the R5 does extremely well but it does have a couple of shortcomings ......... one is with focusing on small birds against a distant background ....... if it doesn't get the bird straightaway and the focus falls on the background, the bird becomes so OOF that the contrast detect can't even recognize it as a subject and it stops focusing ....... 

 DSLRs in general don't suffer from that because they use coincidence range-finding  ........ 

   Wim,
 .........   do you think the great images are just because of the R5 ? ........ and not the photographer and the available subject matter?? ........ that's no reflection on the R5 btw ...... the R5 is a great camera ......

....... so I'll copy/paste BC's format of clever mantras:

" people have been photographing birds with FF format for decades" ........ without cropping........ apparently ...... (really?) .......

replace "cropping" with "eye detect"  
 
 how about? ........ people have been photographing birds with the FF cameras even before the before the R5's eye detect era ........
 
  great though the camera is, it is neither the start of bird photography nor the end of the era of cropping .......