I’ve read Dune, Dune Messiah and Children of Dune but never really went beyond the surface of the story until recently, when I came across a video of Tolkien disliking the novels and a resulting discussion.
It seems that Frank Herbert intended to write a cautionary tale about the dangers of charismatic leaders and the jihads that follow them. The first Dune novel was not much more than an origin story, setting up Paul as an archetypal hero whom people would be inspired to follow. The subsequent books were intended to deepen the story and tell about the wars that followed. People have called it ‘nihilistic’ and ‘devoid of real hope’.
I find it really interesting that Denis Villeneuve seems to be following the spirit of what Herbert intended for Paul’s story, while the books ended up focussed more on the children, from what I remember. I recall hearing that Villeneuve wanted to complete Paul’s story in the third film, and certainly the trailer seems to hold true to that.