Shooting a gun in a game is a simple action. You aim a cursor at a target and press a button to pull the virtual trigger. It’s a simple action, but when you look at a standard controller and all the buttons used for shooting, the action quickly gets complicated. Suddenly there’s a button for looking down the sights of the gun, for reloading the gun, for crouching, for switching guns, for activating a secondary function of the gun. Then, there’s all the complexities not linked to a button: knowing when to reload, how fast each gun reloads, how recoil affects your aim, that looking down the sights improves accuracy, that crouching improves accuracy, that moving decreases accuracy, that running prevents you from shooting, etc., etc. Seen this way, the modern shooter is actually a damned complicated beast.