Statistics don’t seem to work well in the human mind, it has to create it’s own conclusion from the stories of something actually happening.
It’s far more powerful if I tell you 3 stories about how someone not wearing a seat belt all died vs saying “After surveying 1000 accidents, 95% of the time, seat belts save lives.” You’ll come to the conclusion more forcefully with 3 personal incidents than you will with the statistics in all likelihood.
This is somewhat of the same problem of book summaries that have impactful conclusions, where they usually have to lead up to the point by giving stories and/or research to hope you come to the same conclusion as them.
For example, The Sedona Method was a popular book with the subtitle: Your key to lasting happiness, success, peace and emotional well-being. And it takes 432 pages for them to really have a conclusion that says, “You’ll basically get over everything with enough time, right? Why not just get over it right now, since it’s sort of arbitrary when you’ll get over it anyway.” Even though that might be a bastardization of 400+ pages to summarize it in that, I’m basically right, but the problem is, it’s not impactful and you probably didn’t have your life change for the better like reading the actual book would do.
While I believe language is sloppy and inefficiently written often times and can be dramatically shortened while retaining 100% of its value, there’s some “magic” that book summaries lose that keeps most successful people talking about all the books they’ve read fully and NOT talking about all the book summaries they’ve skimmed.