Originally posted by labidas Nope. A7III is miles ahead.
The method is slower, Labidas.
You're missing a dedicated PDAF system, powered by the mirror.
The mirrored AF sensor can use as many pixels as it likes, the onboard PDAF pixels of mirrorless use up real estate that you cannot form a picture from. The camera will try to hide the gaps by baking the RAW, making up values (I think someone mentioned 12 percent of the surface does not read data) but this can lead to banding and artifacts, like all digital processing.
Rarely is the PDAF enough by itself … the usual is actually a hybrid of both CDAF and PDAF, introducing a delay.
As I understand it, amongst the criticisms of the EOS R and the Nikon Z7 is that the autofocus is not as fast as the 5D Mk IV and the D850 they are based on … disturbing for professionals who are being asked to put out a lot of cash and change mounts for native lenses.