The story needs narrative and dialogue to drive the plot along. Don’t write reams of narrative. A vital piece of writing advice is show, not tell. Don’t have eight pages telling the reader about an argument. Show it with a scene.
Sometimes the writer needs to know all about the character’s past but the reader doesn’t. We may not need to know that he owned a hamster when he was eight – unless he’s a serial killer and chewed its ears off, obviously.