There aren't necessarily more stories to tell with Dick and Kory, as Kory changes the kinds of stories they can tell with Dick. And need i bring up RHatOs. Neither are immune from bad characterizations or being passed around. Babs is just easier to slot in and out of Dick's solo life, and vice versa.
Thats why they keep it in the state they do. Like this marriage and it being unearned, it is, but at the same time its isn't cause they purposely keep their relationship in such a stop and go state. Its frustrating but that state makes things more convenient for them to pull it out when they want, and do things like "hey lets get married. Ok sure.".