I liked the book and I was surprised how close to it was the movie, the part tgat got there. And yes, they left out many things, but it’s understandable, because the movie was planned as a “funny movie”, not a “socio-economical movie”. So the book was like “drugs-capitalism-drugs-Vietnam-drugs”, tgey cut out all the “boring” parts, leaving only drugs.
The movie is cool though, but It’s just me always trying to appreciate what is shown to me, and not trying to compare with another media.