It's like Santa, the Easter Bunny or Jesus, when kayfabe is being followed by everyone including the audience, it doesn't matter if the audience knows or suspects. The people who 1) know/suspect it's fake and 2) where that knowing/suspecting ruins it, isn't going to be involved, so the only people left are kids who think it's still real, and adults who don't care and play along. If you're at work or with friends and they start talking about game of thrones or breaking bad or harry potter or bangbus or whatever new movie is out, if you join in but say "you know it's fake right? it makes you look like an idiot, so no-one does it.
