Why does Black Ops 4 not have a single player campaign?

According to many reports, the game's publisher Activision found Black Ops 4's take on a single player campaign to be "too out there" and retooling it would mean it wouldn't be ready in time for release. Also, the single player option has been replaced by a battle royale mode.

The source that reveals information about the game has said that there is a priority on cooperative approaches as a potential stand-in for the typical single player campaign experience. The series is trying to break away from its typical heavily structured gameplay for which it is known for.

The emphasis has been to expand the multiplayer and zombie modes. The developers were trying to develop the multiplayer and zombie modes. The developers were attempting to do something a little different from the traditional campaign.