Yes, Black Ops 3 is still active on Xbox One. Despite being released in 2024, the game continues to have an active player base on the Xbox One platform.
Black Ops takes place between 1961 and 1968 during both the Cold War and the Vietnam War, 16 years to 23 years after the events of World at War. It portrays a secret history of black operations carried out behind enemy lines by the CIA.