The problem with books is that, while there are a lot of good books with good content, 5% of it is good content while 95% is filler material to get the book to a certain amount of pages in order to sell it.
I’m not sure where the disconnect lies, between the people that view this as a huge problem with nonfiction and the rest. I don’t think it’s book selection, because I’ll often read a book where I felt the last half was 90% rehashing, and in the reviews no one else will mention that the author ran out of interesting things to say halfway through.