Theres more to it than that.
Granted, there will be mimes - but when you get to larger productions, where there is a hell of a lot of effort put into polishing the audio, click is vital for things like time based effects (e.g. delays). Theres simply too much going on for sound engineers to be tapping tempos or trying to get players to control their onstage effects to be in sync to an ever changing tempo. Solution = click, and midi timecode. Lets not also forget, for large scale events, you'll need a click for automations on the light show.
Cues is no biggie - why wouldn't you prerecord the cues if you are running to a pre-arranged show? It's making the MDs life a bit easier on the talk back mic.
I know Rick Beato talked about changing up shows - all possible if you mark your loop zones in the arrangements. Like everything, it's all in the prep.
And thats why the best stadium shows are complete mammoth works of art.