"How to win friends and influence people" contains so much self-repetition that it should be easily compressible to four pages, no doubt many people on the Internet have done that. Read one of those instead.
I think the point is, there's many ways to make a point. Communication is hard. Reading a four page overview of a book is not the same experience as reading the actual book. Neither is reading a four page overview written by somebody else.
I also didn't like Carnegie book for the same reason you mentioned, but I wouldn't dismiss it for that reason