It is what the author wrote but it's basically like saying Winnie the Pooh has themes of childhood innocence... Yes. It does, sure, but would you bother writing an essay on it? Deeper reads of the text give you a lot more subtext. Like for instance how the plight of the Fremen and the spice trades mirror the political situations in the Midde East, Atraidies and Harkonnen are rips of Greek and Finnish names with many of the main offworld characters having Biblical (Hebrew or Roman) names while Fremen are specifically sort of coded as Bedouin /Islamic Zen Buddhist mashups and sometimes they straight up speak Arabic. So the offworld Empire gets kind of "Western Civilization" coded and the desire for emancipation is taken over by an inevitable religious fanatism caused by essentially an offworld sympathizer who is the result of hundreds of years of Eugenics becoming a messiah figure basically being a better indigenous people then the indigenous people who are ultimately pawns in a female lead conspiracy that fucked up because of one woman's choice to have actual reproductive autonomy...

Dune's got a lot subtextually going on worth talking about but "Tough conditions tough people" isn't what I find interesting about the story. I get that from a lot of places so it doesn't feel particularly unique or special to the story.