I often feel similarly to this when it comes to anime vs manga. I've explained it to people as the anime with its voice acting, music, motion, and color being able to present a better version of the story. You hit the nail on the head with reading the book after to fill in blanks as well. I like to say the manga often has bonus details, but if I'd read it first, it would spoil the anime, similarly to reading a movie script before watching a movie. Basically no one agrees with me on any of this so I was surprised to see your take being similar to mine.