There’s so much internal monologue in Dune, how else are you going to represent it? The Scifi Channel and Villeneuve both seem to just kind of like, leave it out.
The miniseries doesn’t leave it out so much as work it into conversations that sound like they could have been part of the book, or have the characters wear their hearts on their sleeves more, which is why miniseries Paul seems like he’s always on the verge of a meltdown.