A couple of reasons we encourage using the scene tool:
- Keep things manageable!
- Determining rough scene summaries based on your outline can help keep things manageable and help create coherence in your final screenplay.
- The scene page acts as a quick reference for the screenplay.
-Not only is this a good reminder for current writers in your project, but it's also handy for new writers joining after your project's underway.
-Prevent after-the-fact changes!

When you feel a scene is complete, you can lock it, preventing further changes to that particular scene, and, again, encouraging a coherent script. If your screenplay appears as just one scene to Plotbot, you won't be able to lock any of your screenplay without locking all of it.