> That means that rightsholders can expect at least $3,000 per title (less costs and fees), which will be shared among the rightsholders for that title (if there is more than one rightsholder)

> if there is more than one rightsholder

Again, a publisher will have a whole catalog of books / titles, a non-negligible portion of that the publisher will own the copyright to (no one to split it with). There's all kinds of books outside of novels, there's media tie-ins, IP franchise books (ie Star Wars), childrens books, textbooks / reference materials, etc etc etc. Yes, with novels the author tends to own the copyright, but you're forgetting all of the other kinds of books out there.