Did you ever use rear screen live view AF while hand holding one of those with a telephoto lens for action shots?
In fact I tried that with a 5DsR and a Sigma 60-600 lens, but the results were less than stellar to say the least. That entry level DSLR had no flippy screen either... ;-)
I wrote the above as answer to the comment of "No more unreliable and slow AF with 9 focus points in EFs APS-C cameras". The dual pixel AF part was meant to the other part of the comment about video features in the old cameras (which were not spectacular, true, but more than enough for me.)
I just resent the idea that old cameras are garbage as soon as newer ones turn up. People made great photos 100, 50, 20 10 years ago, with whatever cameras they had.
I do realise that newer cameras have superior AF and fps capabilities, but i have seen good wildlife photos taken with those "EFs APS-C Kameras", so they were not entirely bad.
But let's be entirely honest here:
Nobody needs an R8 Mark II because he/she can not get the "shot" with the R8 Mark I.
Same for R6 III, R6 II and R6. Yes there are differences. But all those cameras are capable.
I have an R, R10, R7 and R6 II, but i still sometimes use my 5DsR or 80D just for fun when out in Nature.
And sometimes, when i am all alone and noone is watching, i even get out my old and (t)rusty 5D Mark II and shoot a few portraits or fashion / cosplay shots in my small studio. And yes, i often only use one of those nine AF points...