I would like to tell the engine to completely stop sending on_input events until told otherwise.
The case being when we are transitioning between states, screens, popups, etc. some buttons will usually animate out while new ones are animating in and it would make sense to disable input until the transitions finish without having to check for state flags inside every botton callback and everywhere else that can receive input.
This becomes helpful when your gui is made out of a different, independent sections that are loaded, enabled and combined in different arrangements depending on game state and you want to preserve the input stack.