Why is unity the most important of all design principles

Imagine a blank canvas. Now imagine a castle in the background, something to represent power or desire. Now imagine a long walk from the castle to a girl in the front wearing poor-looking clothing, representing not being able to achieve power or desire. Or being held back by something. Then the things that surround the walk, forests and moats, etc., represent things that get into the way. Now. When you look at the whole picture, it sends a message. Unity is the little pieces making a story. This story was the creators purpose, making it important. Or this story is how it touches you or you interpret it. So unity makes the big picture from the little details, which is how the art touches you. And that's all important and the reason most things are created in the first place.