What does jump the shark mean??
I don’t know why the term is used to describe the phenomena, but “jump the shark” means that a person or a particular social institution, TV show, etc having achieved its highest level of popularity, importance, and that it is now passed its prime to eventually fade out, away.
It comes from the TV program Happy Days which was very popular but ran out of ideas. The had one of the cool characters (Fonzi) jump over a shark on water skis. The show cratered badly after that and went off air