If an author works with a traditional publisher, they’re using the publisher’s supply chain. They need their book proposal accepted by the publisher. The author needs to apply the publisher’s feedback, even if they don’t agree with it. The publisher will schedule the book’s launch, and the author will follow. The publisher will, hopefully, put resources into promoting the book through publicity. The author may be able to influence the publisher’s decisions, but the publisher retains control. The author doesn’t have control.

In exchange, once they sign a deal, the author doesn’t need to worry about the supply chain, either. They get to focus on the book. Some authors may prefer this, because it feels like less work for them.

If you flip this idea to the opposite extreme, consider the author who publishes independently. They need to build their own supply chain. They need to hire their own designer and editor. They set up their own online store. They need to promote the book themselves. If they want to make print versions of books, they need to find a printer. 

The author doesn’t get to sit back and just focus on the book. Whenever something goes wrong, the author needs to find a solution. It’s a lot of work that has nothing to do with writing a book. 

The reward is the author gets greater control over their own supply chain, every step along the way. The supply chain skills they have built means even if a publisher rejects their book proposal, they can still work on it independently. 

An author who can do both will have more options.