Sometimes its easy to fall into the trap of feeling like Patricia Arquette in A Nightmare on Elm Street 3: Dream Warriors in Nancy’s house running in place on sticky red goo. Work, work, and more work only leads to additional work in a never-ending cycle. The nature of work is it never ends until you change jobs or retire. If your work is your life, as with artists and writers then there may be no end until your end. Writing may be one of the worst offenders for endless work, especially on large projects. A series is a perfect example of this. It could take years to complete. Consider Sue Grafton and her one book for each letter in the alphabet, or Stephen King weaving connections between dozens of books forming a super background story.
Role-playing games have the same glorious problem. A particular setting may have dozens of books. If the publisher is lucky there will be multiple authors contributing to this mass world. Sometimes a lot of them will be written by the owner of the company who created everything from the ground up in and out of the books and uses an overreaching view of the setting–often enough multiple settings–to maintain a specific vision. That can include re-writing bits up to re-writing entire books. This can be done because the freelancer is writing a derivative work. Movie novelisations and writing for copyrighted settings would be derivative works as well and subject to revision control by the copyright owner. This is as opposed to the novelists who write and control their own creations.
Music: More Human Than Human by White Zombie.