My issue though is that at the end of the day Lord of the Rings has clear heroes and clear villains. Even the heroes who are tempted by the dark side or make mistakes are given opportunities to redeem themselves. There's one clear big bad, and there's a battle for freedom to keep Middle-Earth free from Sauron's rule.
In Dune, it's a bit different. Even if you have the Harkonnens as the clear villains, after the first novel, things get a lot murkier. If you truly want to adapt those novels, it will be difficult to film them and make them not just understandable to a general audience but digestible. The novels don't really have a traditional narrative structure. A lot of weird things happen.
In Dune, the so called good guys are not really all that good and they perform a lot of questionable acts, especially Paul.
On a visual level, yes Dune is very possible to pull off at this point in terms of visuals, technology, production design, etc. At the same time, pulling off Dune will not be cheap. So it's tough for me to imagine how the studio will be willing to invest the books' visual ambitions and not want to make changes to dumb it down and make it more audience friendly.