The book assumes a basic knowledge of physics and cosmology so it does not spend half the book reviewing basics like many pop physics books do.
[1] https://press.uchicago.edu/ucp/books/book/chicago/B/bo244963...
The very useful Open Syllabus Project collects syllabi and lists the most popular books, etc.: https://www.opensyllabus.org/
A professor's course materials may suit your need.
Did _you_ read that book?
There however definitely was a piece of media that captured public minds and educated them about the cosmos. And that was the show Cosmos. The original of course. Not the NDT drivel.
I suspect that a popsci book becoming a bestseller creates a larger-than-the-usual-nerds audience, a big part of which lacks the motivation to actually finish it. I expect that in places like this you will find higher frequency of people who have actually read it.
Moreover, when i read the book i did not have easy access to pop-sci sources as a (practically pre-internet) teenager in a small town of a small country, like i would have had today. I got upon a booklet of a small publishing house with the titles of translated pop-sci books and would order them from a local bookstore. Maybe if I was already familiar enough with the topic through youtube videos etc I would not have finished either.
TBF the methodology and hypotheses that it's based on aren't that bad. I'm sure Amazon has better data, but for a "publicly accessible" data (at that time) I can see it. The problem is that while lots of people might abandon the book, that doesn't mean that still loads of people don't read it fully. They are, after all, extremely popular books. Obviously some people will have received / impulse bought / FOMO / new year resolution / etc the books, but from the sales numbers that's still a lot of people that did enjoy them. Marketing aside, the book is pretty approachable, like were Sagan's books and so on.
BTW, as non-USAian, I never saw Cosmos and never heard of NDT.
However I still doubt the methodology. It is not obvious for me that if a book was read in full, then highlights from it would be distributed uniformly all over the book.
Never heard of the "people don't actually read it" meme.
I've never seen cosmos.
Maybe godel, escher, bach would be a better "book that people talked about but never read"
Fun fact: The very first book ever sold on Amazon was "Fluid Concepts And Creative Analogies: Computer Models Of The Fundamental Mechanisms Of Thought" also by Douglas Hofstadter