Question: why black ops 4 is not on steam?
Answer: Why is there no Black Ops 4 Steam version? Call of Duty: Black Ops 4 is made by Treyarch and published by Activision. Following the merger of Activision and Vivendi Games in 2008, Activision Blizzard was founded. So it naturally follows that an Activision-published game is sold on the Blizzard App only.