I might have some perspective on this... simply because I went through OW certification twice, with about 30+ years between them.
The first time was a course offered, I think, by the local Y. It was LOTS of book material, lots of emphasis on working tables (Navy), knowing the hardware. I remember a whole section of the book (Think it was "The New Science of Skin and SCUBA Diving") showing the difference between different types of regulators, upstream, downstream, balanced vs unbalanced, pluses and minuses of each. I think we had 4 classroom sessions, each several hours long. The pool sessions (of which there were many) were almost 'military' in focus, I don't want to say that the instructors tried to kill us, but there was a lot of 'pulling masks off, shutting off air' type stuff. I recall doing skills in a blacked out mask. There was also an exercise where you dove to the bottom, doffed your gear, swam up, dove back down and re-donned your gear. We cleared masks upright, horizontal, swimming on our sides. And we did all of it again and again.
I do know that all those skills were really burned into the brain, so that response was automatic.
Never really did anymore after that due to extraneous circumstances, until I went to Florida Keys for a reunion earlier this year. A cousin took me on an easy dive in the gulf, and I was hooked again. I realized how much equipment had changed, most of it wasn't even mentioned (or existent) when I first did it.
I got trained by a local instructor, and it surprised me how 'light' on content the book and class session (1) was. It also really seemed that the agency (PADI) really tried to minimize any real mention of the dangers. When I did it the first time, there was a lot of "If you

up and do this... you can die, and it won't be a pretty death". I feel like the current OW / AOW training is designed to make it as approachable and easy to learn as possible. I came out of it with a number of 'do these things' but no real appreciation for the "why" behind the guidance. As a professional trainer myself (computer stuff) I found it to be a good light overview, but not any depth to it.
The water skills were a lot easier too, pretty much everything at own pace, it was a walk in the park for me. I've had the advantage of always being comfortable in the water. It seems that the skills that were drilled into me long ago still were there, so it was fun. I also saw where if somebody was coming in with zero experience and no basic comfort level in the water they would be ok in a nice controlled dive in very mild conditions, but could be in a lot of trouble if things went sideways somehow.
I've since hooked up with some divers that are helping me improve my skills, and of course, scubaboard is a font of information.
Just my .02 (or possibly a bit more)
Steve