It’s also possible that The Joker’s death was what led Bruce to leave Gotham City behind.
Maybe he was too afraid that he would turn into his “Crisis on Infinite Earths” counterpart, a darker Batman who killed Superman and countless others.
However, it’s hard to tell whether viewers will ever get any confirmation on that front.
The moment was also a clever way for the Batwoman writers to finally reference the Clown Prince of Crime while delivering a believable reason why he’ll probably never show up in the Arrowvers as a major threat.