Did the Joker not need the origin story it got?

Last week, I watched Joker starring Joaquin Phoenix as the title role. I’ve since been reading several articles concerning the controversy with film discussing how the whole point of the Joker was that he had no backstory and was just an evil being who desired to cause chaos and how this move ascribes what some deem to be unwanted logic to his actions. In this Vox movie critique, I get the sense that Wilkinson is describing the frustration many must have felt about how the Joker was not unpredictable and the film was inert.