I’m with @Austinlad on this one. The script is the core from which everything else flows. For example, I hated the movie Avatar, because it had a lousy script that a child could have written. I knew from the opening scenes everything that was going to happen in the entire movie, and I actually got up and walked out. In discussing the plot with a friend, I later learned that my assumptions had been correct
The script is important, because it’s what the director bases his vision on. It’s what the actors look to for grounding their characters. It informs the cameramen about the shots that are going to draw out the subtleties of the themes. And it does so much more.
The script is more than dialog. It is the center of a great enterprise ultimately becoming a movie.