Seems like every work wiki I encounter is always messy. I think one of the reasons for this is that users believe modifying or deleting a page would be permanent. This is usually not the case: many wikis have versioning features. But they’re always hidden away and I wonder if people just forget they’re there. The version history also seem to be tied to pages, as oppose to the wiki as a whole, meaning that recovering a deleted page is a different set of actions than comparing an older version of an existing page.
Maybe the way to solve both issues is to have a single big “version” picker at the top-left of the screen. This doesn’t recover just the current page. It recovers the entire site, and allows the user to visit the state of the wiki at any time: a week ago, or a month ago, all the way to the beginning of time. All the deleted pages will be restored, and previous versions of updated pages will be recalled (new pages will disappear, which may or may not be what you’d want). This will work in concert with the page-specific version history, which I think is still needed for actually reverting pages to their previous version.
It’s almost like the entire wiki is backed by a Git. I guess that’s what I’m suggesting: wiki’s should use something like Git for this, only with a much nicer UI.