> I'm utterly bewildered that there's no official documentation of this stuff though.I don't know if there is or isn't official documentation everything you might typically want to know for Apple products. Clearly, they don't document the answer to every question that anyone might ever ask, but they do document many things that you might not think they do.
I know this because often when I Google for how to do something on a Mac, I often end up on some Apple page that tells me how to accomplish what I want. E.g., a page that documents a bunch of MacOS keyboard shortcuts, or what have you.
Of course, one problem is churn. I.e., the features in the software are changing frequently, and consequently, documentation can get quickly out of date. Also, Apple is likely to be cooperating with book authors. There is the "Missing Manual" series, which often seems to contain a lot of useful information (though, as I mentioned sometimes out-of-date), and I'm sure that David Pogue and friends don't figure all of this out via just trial and error. It seems like they must get some sort of assistance from Apple in the form of release notes or rough documentation, or something.