Do you think a pretty simple or basic storyline can still create a complex story? I would like to think it can. I'm a pantser so it's when I finish my story that I can fully breakdown and see clearly the plot line. But even when I am writing, I do try to keep the plot kind of simple. I don't know if simple is the right word. I'm pretty plot driven for a literary writer, but that doesn't mean I have a complex plot structure I would like to think the complexities from a story come from more than just the plot. But is this thought making things harder on myself? What do you guys think? Where do the complexities of stories come from? How complex are your plots (talking just the plot -- not world building or character development)? And what do complexities in a story mean to you?
World building and character development have an influence on the plot. If the simple plot is defeat the bad guy, how does the character's ethics or morals get challenged in reaching that goal? How does the world/society create problems reaching that goal? There is a quote I keep in mind for the military for cases like this. "It maybe simple, but that doesn't mean it is easy."
I would say world building and character development have more of an influence on the overall story, but plot is something different. I mean you can break down any plot to it's simplest terms without those things whether it's a complex or a simple plot. Character and setting can make a story more complex even when the basis of the plot is pretty simple.
What part of the story is complex will be more often than not dictated by the focus of the author. J.R.R. Tolkien's world-building is more complex than his characters. George R.R. Martin's characters are more complex than his world-building. The complexity of Finengans Wake lies in its language and symbolism; the complexity of Nabokov's Lolita lies in its difficult subject matter.
Martin did a deep dive into history, and stitched together many different events, for his song of fire and ice.
Not sure if this necessarily answers your question, but I couldn't help but think of this segment from Joseph Anderson's video: I think he does a nice job summarizing the concept of complexity in stories or I guess rather the purpose of complexity.