Why the Joker Sequel Destroyed the Fanbase

The sequel to the original Joker movie was largely disliked due to several reasons: it deviated significantly from the themes and plot of the first movie, it was slow and boring according to audiences, the musical aspect didn't add to the plot or character development, and the character of Harley Quinn was underused and underwritten. Additionally, the film seemed to be made with the primary intention of making money rather than telling a compelling story.

via Joker: Folie a Deux - How One Movie Destroyed an Entire Fanbase