Why was the multi image technique abandoned?

Here is an idea for a concept film- I don't have it worked out fully yet. A person with a split personality goes through an entire film with the screen divided in half. Each side of the screen represents how each of the personalities experiences the same event that is happening.

We all have at least two people in us. We have all experienced doing something and feeling somebody else in us rebelling against it or is scared to death of the consequences. What is this could be shown?