Well, I disagree regarding Villeneuve's Dune films. I think both are brilliant, though they do need a big, preferably huge (ie IMAX) screen and top range sound system to be fully appreciated. There's a reason I often jokingly refer to them as "Lawrence of Arrakis".

But I do agree that a film should not necessarily be a slavish adaptation of the novel. For full thoughts on that issue, with examples, here's something I wrote a while ago that I think might interest you, based on what you said. :)

Why the Book Isn’t Always Better than the Film | Frame Rated (medium.com)