I feel like there's some moment in the second season where the writers went--oh, fuck, they're funny, got it. And then the show got license to use the fact that they had two actors with excellent comedic timing who could pull off a joke. They really recognized what finds they had in their leads, and were able to make the show a lot more complex because of it. The mix of humor and seriousness is one of my favorite things about the show, too.