Yes, but Batman and the joker need each other. Batman won’t kill him because that will prove jokers point; that he’s just as bad as him.
This is why joker begs and WANTS to be killed by Batman. And this is why Batman never kills him, only gets him arrested.
They can laugh together because they know neither will ever win. There’s nothing Batman can do that he hasn’t already done……. Unless he kills him
But we know Bruce doesn’t believe in that and believes that killing doesn’t have to be the answer. So joker is gonna keep doing whatever it takes to get killed by him so that Batman will have to live knowing he’s taken a life…. Because “it was the only answer”