Documentation style is a balance between what people find easy to read, and what authors are going to actually write. While it would be nice for beginners if people wrote customized tutorials that explained material in perltoot in every module, that realistically is not going to happen. And besides which, experienced Perl programmers won't want to spend time wading through a recitation of standard material.

The style popular in Perl is one from Unix. It is terse, accurate, and to the point. Because it is terse, it is easy for a module writer to follow the style and actually document their complete module. So they do. Were it more verbose, it would be harder to write hence less often written, and harder to audit for errors, and therefore would be less accurate.

But if you want to get a book, well you are going to have to buy it. Because that is not the way that POD is used, and people are generally not going to go out and verbosely document just for fun...