Of course, but a phone book is simply an alphabetical list, with the sole content being a self-contained single string of digits with only one interpretation.
A manual for a program as complex as Cubase is nowhere near as linear, has many interrelations with material elsewhere in the manual, nor do the headings always convey the complete contents below them. And the complex nature of the material is not always readily understood from the text and pictures.
Just a few tedious ventures into the manual can be enough to dissuade one from choosing it as the first point of call.
I often find that the material seems to need experience with the program before one can understand it. If one is at the start of the experience ladder, then consultation with experienced users can short-circuit a lot of grief, and can be a whole lot quicker.
As a professional tech writer, I think the manual would need to be several times larger to adequately cover the knowledge and procedures required for a beginner. As it is, it is a rough indicator of Cubase’s facilities and a few of the possible usage scenarios.