Personally, I'd rather read 100 pages of clear, concise prose than 1000 pages of the author rambling and making sure everybody's on the same page and adding his buddy's research about something remotely related to the subject and blah blah blah...
In fact, that someone else may even be yourself at some later date - I have found that some previously read books make more sense and become more enjoyable after having personal life experiences that enable you to relate emotionally, or just get you interested in the subject.
... maybe you are reading too slow. I know I was reading faster when I was much younger
Turns out, blog-posts aren't really as sellable as books.
Think of it as being like food, or some other sensual pleasure you enjoy.
If you could condense all meals into a pill and just swallow it would you? Probably not, because sometimes you want to just 'get the sustenance' and sometimes you want to enjoy the experience, to revel in the presentation, flavour, texture and company you're with. Books are exactly the same. There are times when the we want the key pieces. But sometimes, fiction and otherwise, it's worth enjoying the writing itself, the mental images that are created, the use of language, rhytmn and flow to make both major points and to explore subtleties.
For a book about the Art of explaining things it sure did a lousy job of getting to the point.
Often audio book versions of books are abridged. You might try those for the classics. If you get a good narrator it can add to the experience as well.