Lord of the Rings: Aragorn

Dirk Pit does not have a character arc in any of the Clive Kussler novels. He is simply Dirk Pit and those books are wildly successful. So why are we reading them? Or why are people reading them? I have no idea. Let's go to something that we all know a little bit better, Lord of the Rings. Aragorn was given a character arc when in the books I never really saw one for him. There was no Iowa, I won't make a good king. Yet the movies, they added that in. The protagonist in those stories seems to be archaeological science.