Currently, all pages are published by default. You can flip the switch to deliberately un-publish a page. This is backwards to how it should be. A page should not be published by default, but rather published deliberately by command of the user (either by flipping the switch, or using an appropriate button labelled something like "Publish").
I have the following use-case: I work in a team with multiple developers. We use wiki.js to create documentation for our product. Since we work on it in parallel, we also have to each create different parts of a given page of documentation. Our customer only has read access to the wiki and thus can only see published pages. It would make a lot of sense for us to publish a page when its ready, not having to remember marking it as un-ready when creating it.