This sound comes from the user interface audio style associated with Team Fortress 2, Valve's class-based multiplayer shooter released in 2007. Short TF2 menu sounds became popular outside the game because they are instantly readable and easy to drop into montage edits, gaming memes and parody interfaces. Creators keep using this button click because it is brief, recognizable and versatile, especially when a clip needs a clean confirmation sound without the bigger impact of a dramatic hit or buzzer.