That is an interesting article that is probably new information to many people who enter photography with a modern DSLR as their first good camera - but for some of us, who grew up with manual focus lenses, black and white film, and even non-auto aperture lenses, it really is not new information - but 60-70 year old information that has been lost or discarded by manufacturers. Most lenses these days don't even offer a depth of field scale and I know a lot of shooters who have no idea what a depth of preview button on the side of their lens mount is for.
In the rush to build cameras with faster and faster ISOs, it seems that lots of camera manufacturers have forgotten how interesting it can be to shoot with an ISO of 5 or 10 or 12. To do that with a modern camera requires neutral density filters - wouldn't it be nice to just dial your ISO back to 4 or 6 instead of adding neutral density stacks to the front of your lens?
As for manual focus, I suspect modern AF on my 1DX Mk II is far more accurate most times than I am. I do restrict myself to a single small AF point that I decide where to precisely place, unless the light or subject movement prevents me from doing that. Or one can grab a 16mm lens and an f8 aperture and skip worrying about focus entirely 😱
I do use manual focus for shooting stars at night - for that I use Live View and 10x magnification. But then stars move pretty slowly at night.
I have a good friend who says he always shoots ( tongue in cheek ) with his camera in P mode - for pretty!