The idea is to promote writing. I’m thinking there should exist a website where users can post small but big enough texts that captures the story. Not necessarily like the backside of a book. I mean enough text for you to build your imagination on. Inspired by open source it could also be a good thing to fail fast. Some ideas for books are better than others. Feedback on the small part could perhaps help you decide which of your ideas to proceed with. This will train you in creating starting ideas for books. Hopefully then with a very good idea your book will be easy to write.