Is it really just ends up in the same place, except, Arthur is dead. Literally, he did all that and ended up back to square one. In the first he gets beat down by society and becomes the joker. In the second he gets beat down and then comes to accept he's not the joker and is back to being Arthur, just the same sad, depressed, kind of pathetic man. The entire second movie is a meta commentary on how people view the first one, just by using Joker and basically treating him as the movie and franchise. It's not trying to be something special, it doesn't want to be seen as this big movement thing it wants to be seen as, well, just a movie about a mentally ill guy and nothing more, so it tears itself down, and kills it, while basically saying "It's not what you want it to be or think it is. It's sad and pathetic, and here, now it's dead." That's what the entire movie is about. And the guy that kills Arthur, is really just a nod to Heath Ledgers joker, to the point I think if this movie was viewed positively, they'd make that connection more explicit.