you do understand that the joker is in the wrong here, right? like in this scene he's a mentally i'll man saying that killing people is funny.
if you genuinely believe that existence has an inherent negative value then i strongly suggest you seek help, and i don't mean that to be facetious. antinatalism is depression turned into a moral philosophy, it posits itself as a solution to suffering by offering an unrealizable future, but really it's an excuse to not even attempt to make the world better.