While Dune takes place on an imagined planet (though purportedly "real," that is, following some canon of physical laws), the city of Arakeen, the imperial center, seems to have no infrastructure. Or, more accurately, while it has immense walls, buildings, rooms, staging areas, warehouses, and such, it doesn't seem to have any toilets (and if they exist, what is the infrastructure on a desert planet to keep them clean and sanitary?). And while a kitchen is mentioned by Baron Vladimir Harkonnen as he eats a meal in front of the paralyzed Duke Leto, no one else ever seems to sit down for dinner or, for that matter, clean the plates after the meal is done.

The Fremen have the excuse that their suits recycle all things watery in the body, though there's no explanation, in the movie, at least, for how poop is processed. (And how and where do those suits get made? There must be fabrication sites—and from where do the raw materials come from?)

Perhaps I shouldn't be surprised that an action movie wouldn't want to spend screen time and real estate on explaining how people brush their teeth in the morning (and where all the spit goes when it goes down the drain) because the realness that it goes for is a cinematic realness that ignores common sense and actual lived life for the purpose of anesthetizing logic for the sake of trading on fantasies. Dune may think it presents a "real" world, but it really only presents enough detail to create an armature for holding up its fables and fictions. In this world, people don't pee, shower, digest, give off smells—that would distract from the "magic."

Of course, the movie's blindness to the frameworks that hold up the whole only reflects a real-world blindness to our real-world infrastructure that keeps masses of people alive and relatively healthy as they live. People who live in countries where water always comes out of faucets like taking such systems for granted; thinking about them and about paying to keep them intact takes away their magic, which causes the pain felt by humans when they have to make decisions.

Water systems, energy grids, roads, bridges—essentially everything that makes a modern mass society possible without descent into war—must be maintained. While it might be nice to imagine that the toothpaste spit gone down the drain has miraculously disappeared, it will not be so nice when the aging sewer pipe that whisks it away suddenly fractures and basements feel the wrath of flood and feces.

Perhaps—one can dream—part 2 of Dune will foreground the civil engineers who make the world possible. Legions of them will march forward with their neonized safety vests, hard hats and gear belts buttressed by the armamentarium of science and beauty to build a world in which people can live full, healthy lives while the parasitic royalty that feed off their efforts engage in annihilating battles somewhere in the distant background until they've eliminated themselves for the benefit of us all.

Denis Villeneuve, are  you listening?

P.S.—For a humorous take on what realism in film might look like, watch this piece by David Mitchell and Robert Webb about a director who believes in realism a little bit too much: https://www.youtube.com/watch?v=HtQNULEudss