And I think that would make for a worse show. There is need for some normal crimefighting episodes in stuff like The Flash and iZombie. They want to solve crimes, we need to see them doing so.
You can fight crime and progress the story they're not really binary options. iZombie does a pretty decent job at this. I just find "baddie of the week" episodes where absolutely nothing progresses (to include character development) to be a waste of time.