Most of the books, for example, introduce a radical new idea and then elaborate on that needlessly for 400 pages. I found Sapiens to be one such book.
Even if the idea/premise is insightful, there is often a lot of redundancy in the pages. We should value brevity more.
Of course, this might not apply to all books. Textbooks/Reference books can happily coexist with online tutorials/blogs. Even certain nonfiction books (Thinking Fast and Slow comes to mind) might be best presented in a book format.