Perspective
Consider:
Why can we tell the same seven stories (Plots) without getting bored by hearing the same story over and over again? Why does changing little details matter?
Point of View may refer to who is telling the story, but Perspective refers to the story's true protagonist. Who are we rooting for to win in the story? Who are we supposed to sympathize with?
Tone refers to the author's attitude or feelings towards the events and topic of the story. When changing a story's perspective, the tone usually changes as well, since perspective is based on opinion and belief.
Theme refers to the general messages or morals of the story. While stories have multiple themes, there is usually one primary theme seen throughout the entire story (Specific enough to be applicable to the story's unique perspective and tone, but broad enough to be applicable to other stories and real-life situations)
So what keeps us interested in stories that follow a very narrow selection of plot lines?
There's an old saying: If three people witness the same traffic accident from the same angle, the officer will get three different stories of the accident from them.
This means that while the plots of stories may never change, the individual perspective changes, and no two individuals are alike. When two individuals tell the same story, we can get two different tones, two different opinions on the topic, and thus two different themes.
This is why perspective matters in story-telling and writing.
.... so remember, when analyzing and comparing literature, the details of the plot are only surface observations. To go deeper, look for differences in perspective, tone, and theme!