I have a particular disdain for the profanity-laden slop that is works penned by Mark Manson. He's not alone as most "self-help" books are trash reads that only serve as some form of cathartic release to their readers. That's not to say all books in the genre are useless. I have recommended Cal Newport's works before but they very much suffer from "this 300 page book could have been a blog post" levels of verbosity.
A huge amount of nonfiction work is overlong. Many nonfiction works could be condensed to an essay or even just a blurb.
A wasted opportunity to explore related ideas.