For some reason, I have always found stories that portray dragons as having beast-level intelligence, even relatively high-level intelligence, to be rather annoying. I can find the story, etc. to be quite entertaining in its own right, despite that, but the annoyance is always there...
It is also always disappointing to come across a new story or series that I am not yet familiar with that includes dragons, only to find that they are little more than subservient beasts.
What is so hard about righting stories where dragons are actually intelligent creatures, and actively-participating protagonists in the story? It wouldn't even bother me if they weren't the main character, just so long as they were portrayed as people, just as much as any other non-dragon characters.
Finding stories that do that, let alone ones that are good and well-told, is a challenge.