CAF doesn't work with the MC21 and EF lenses for the S5. I have heard that somehow it works for the S5II, probably because they mostly ditched DFD.
Actually yes it is, with useable CAF I would have had a far higher keeper rate which is why I am now back on the Canon train. I have heard it all, who needs AF, real shooters use MF, Hollywood cinema cameras all use MF etc....but none of that matters to me when I am shooting an event and flying a camera on a gimbal that has no AF or shooting handheld at an event or for a project.
If I had a support team and a dedicated focus puller and all of the Hollywood bells and whistles I wouldn't care about AF either; in fact I still use MF quite often even with Canon bodies for many situations such as talking heads, rack focusing, shooting through obstructions such as grass or fences where the AF will pick the wrong subject, when it is too dark, etc; I have no problems manually focusing when the situation calls for it; but having to manually focus for every shot will absolutely yield more throw aways than with a camera with useable CAF unless you have a dedicated focus puller, or something else contributing to your success (wider lens, simpler scenes, more time to prepare, etc.)
It is easy to cherry pick specific instances where MF looks fine, and when you have the time to properly block a scene and dial in the focus or repeat a scene then that's all good and well, especially if you are shooting as a hobbyist where no one cares about the footage you didn't get; in fact I have plenty of tack sharp footage in many projects that were shot with MF, but try MF shooting even one of my events and you will encounter a much different story.
My typical event has a shotlist that is multiple pages (vendors, VIPs, activities, talking heads, etc.), I am shooting photos and video, going from indoors to outdoors and back, working with the audience or attendees who will only stand still for a few seconds for a picture, and maybe a few seconds more for a quick video clip, and all the while everyone and nearly everything is in motion, and that is all handheld, I haven't even started talking about shooting on a gimbal yet; and yes I did it for years with the GH5 and S5; but at the end of the day it was completely exhausting and limiting to always have to work within the limitations of MF, to never know if a shot was sharp until reviewing it later, etc.
So yes, it is my opinion that in 2023 if your keeper rate is low due to lack of useable CAF then it is absolutely the camera's fault. MF is great and even necessary for many scenarios, but when shooting as a OMB so is AF. Both have strengths and weaknesses and there is nothing wrong with having the option to use AF when that particular shot can be better served by AF allowing you to focus on other things (no pun intended).