Almost every company has had an internal wiki and most of those wikis are now a graveyard somebody links to apologetically. They die in three recognisable ways, and one habit prevents all three, which is why it is worth naming.
Death one: nobody owns anything
Pages are created by whoever needed them and then belong to no one. Two years later the wiki is full and unusable, because there is no way to tell which pages somebody would still defend. This is the common case and it is entirely preventable at creation time.
Death two: the structure came from the org chart
Sections named after departments feel obvious and fail readers, who arrive with a problem rather than a department. The reorganisation then orphans whole branches, and nobody is quite responsible for moving them.
Death three: it became the place everything goes
Meeting notes, policies, project plans, onboarding, one person's scratch pad. Every one of those has a different lifespan and a different reader, and mixing them means no cadence can be applied to any of them.
The habit that prevents all three
Requiring a named owner and a review date before a page is published. It stops the graveyard, because unowned pages never get created; it prunes the structure, because owners will not carry categories nobody reads; and it limits the dumping, because nobody volunteers to own somebody else's meeting notes.
Resurrecting a dead one
Do not migrate it. Start the question list fresh, write the twenty articles that answer them, and check the old wiki only when writing each one. Most of what is there will not survive contact with the question it was supposedly answering.
Questions people ask about internal wiki
Is a wiki different from a knowledge base?
In practice the word signals the audience: wiki for internal and editable by many, knowledge base for customer-facing and edited by few. The failure modes are identical.
Should everyone be able to edit?
Editing, usually yes. Publishing a NEW page, ideally with an owner attached. Open editing of existing pages is healthy; unrestricted creation is what fills the graveyard.
How do we know ours is dying?
Count the pages nobody has confirmed in a year and divide by the total. If you cannot compute that at all, the answer is most of them.