I probably should stay away from this topic, but passion overrules reason so here goes...
I've been focussing manually for a little over 40 years. One of my gripes with AF is the concept of the focus 'point', singular or plural, makes no difference. I typically work with long lenses & with subjects that preclude much depth of field so no matter what I do there are going to be areas in the picture that are out of focus. With this in mind I have to pick what I want to be in focus and most often it's a critter's eye.
The areas I want to be in focus can be anywhere in the field of view because I can't direct my subjects and they can and frequently do move quickly and often anywhere in the field of view. I want to focus on the eye and their heads bob up, down, left, right, backwards and forwards and numerous other directions that defy description in the english language. Some also have an internal clock that I'd swear operates at several orders of magnitude faster than my own. They don't obey the camera makers' direction either because they're as likely as not to pause their motions perfectly lined up with a focus point (leave alone for the moment whether the focus point has been calibrated correctly, is responsive, or functions well at the lens' aperture).
Re-positioning the camera to place a focus point on a bird's eye takes too much time and can turn my chosen composition to one destined for bit recycling. Re-composing after focus likewise is not an option because in the time it takes to re-compose the critter will have moved. I want to focus as-composed anywhere in the field of view, not just where the camera's maker thinks the subject is likely to be.
Gripe #2: focus 'points' are not really points. They're small regions and the camera's maker decides how to prioritize focus on the pixels within that region. Thoughtfully they've allowed the user to select from several prioritizing algorithms but am I going to dive into a camera's menu while a warbler is jinking around in a bush? I think not.
Gripe #3: AF micro-adjust. I ought to give camera makers credit where credit is due, they've finally acknowledged that the PDAF they'd been telling us for years was perfectly accurate (and more perfectly accurate with each new model) wasn't so accurate after all. Enough said.
What has AF allowed us to accomplish? It has allowed us to make the same photos as anyone else with the same equipment. Bald Eagle flying with fish at Conowingo Dam? Dime a dozen. Photographing birds in flight is now such a cliche that it has its own acronym: BIF. If technology has enabled this and the technology is widely available how many truly original photos are enabled by the technology? Do you want the make the photos that the camera makers expect you to make or do you want to make your own?
Manual focus is too slow. Really? How about some BIF:
(crop from lower left corner of image)
A good viewfinder adjusted for the users' eyes and good ergonomic design goes a long way toward making manual focus easy. The rest is practice.
End of rant. For now.