Dune, as a novel, was very much invested in an exploration of ecology and sociology, and how the two intermix. People made by their environment, and the environment being made by its people. And, in the midst of it, it created characters with lots of personal agency and accountability, a very humanist outlook for the far, far off future. There's a discussion Herbert was having here with Asimov and Foundation, a bit with Sagan, and you see them twisting together book after book. For Herbert, I'd also push you towards the Destination: Void books, since those take a similar detour as the later Foundations.
Arrakis was constructed as a system less than a character. It has a geography, patterns, and rules. The people that live there are integrated with all those systems so much so as to have become part of its ecology, and indeed in the case of the Fremen, have begun to guide that ecology. Those that are merely visiting seem to always be iceskating uphill, to borrow a phrase, until they learn to follow the current. Most don't, but those willing to learn do. There's a lovely appendix with a story about Pardot Kynes; it's one of the standout features of Dune.
Getting back to Villeneuve's sweve: Paul is a passenger on a runaway destiny going downhill very fast. The book details how he comes to realize why the brakes have come off, what's at the bottom of the hill (later books explain that it's actually been a mountain all along), and how he decides to let go of the wheel and let gravity take its course. Dune Messiah takes over just before his destiny reaches the bottom (of a valley) and tries to throw some hay in the way, but then we discover that Paul's been wearing rollerskates the whole time and ejecting him from the vehicle just meant that you now have two destinies rolling down the hill at high speed.
Villeneuve's Dune inverts the curve; Paul find himself walking uphill through much of his Part One arc, cresting midway through Part Two and then coasting downwards into Messianic Despotism at the conclusion. This deviates from book where Paul finds himself awash of Fremen custom and propelled by circumstance, guided along by Chani (herself deeply embedded in the Fremen faith and a chieftess in waiting), forced into the leadership of a Fremen awakening that quickly expands beyond his control. In Villeneuve's rendition, Paul leverages prophecy to spur the Fremen out of inaction, to enact revenge, to lift him into a throne. Chani, by contrast, sees exactly what her people do not: that Paul is just another oppressor, but one who leads with a treat rather than the leash. The divergence occurs proper at the moment that Paul takes the Waters of Life, and why.
This speaks to more recent readings of Herbert's work, which (Cough, A-W-F Unlimited) you'll probably note probably weren't on Frank's mind at the time. It makes me ponder how Paul will be characterized in Part Three: Irredeemable Tyrant (who used to be so nice)? Faltering hero (who could have avoided all this)?
We know who Chani will be: she sets off the bomb at the end.
