When you sit down to began writing a script you are opening a door into another world. Imagine having a blank canvas. You create the neighborhood, the surrounding counties, the administration to run it, and all the people who live inside this world. Then you do it over and over again. Every time you write a script you create a different world.
Look at it this way. Being an author is an independent activity. You, alone, sit for hours creating a story you plan to distribute to a multitude of readers. You are the only person in your village of those who surround you, who can create the story. Once the story is complete, you do one of two things. The story is submitted to a traditional publisher, then you sit back and wait for an acceptance or a rejection letter. Or, as a self-published author you will move to the next steps to prepare your book for public consumption. This is the point where you turn to what I call a village. First up are the editors, who review the project (story) for errors or clarification. Next, you hire a graphic artist to create your book cover, and then your marketing team to plan how the story will be introduced to the public.