Well, I suppose like all things it is a topic of debate. Fish intelligence is still very contested afaik, since it's difficult to evaluate the intelligence of organisms who sense and interact with the world in such a different way from us. Honestly I think cephalopod research has only gotten as far as it has because manual dexterity and color are some of the easiest things for humans to understand. For a fish that doesn't have prehensile appendages and doesn't interact with color in an obviously complex way? It's hard to think of where to start.