IMO most popular non-fiction books don't have enough content to justify their length.
I'm not saying that the content is bad, or you shouldn't buy the book. The book is just padded out so you feel better about buying it. Who would buy a 40-page book for $15? The book gets padded out to 200 pages by repeating itself, adding filler sections, anecdotes, graphic design choices, etc.
I am happy to see books get shorter if it means that they have less filler.
I'm not saying that the content is bad, or you shouldn't buy the book. The book is just padded out so you feel better about buying it. Who would buy a 40-page book for $15? The book gets padded out to 200 pages by repeating itself, adding filler sections, anecdotes, graphic design choices, etc.
I am happy to see books get shorter if it means that they have less filler.