"I was watching one where it seemed like the "save the world" goal scrolled off the history buffer and the hero was off on side quest after side quest with the main goal forgotten."

That's hardly a problem unique to AI-generated low budget dramas. That's a problem that literally derailed the latter seasons of Game of Thrones, a show with a huge budget, massive human writer's room, drawing from award winning source material.

People ascribe every problem to AI, instead of just recognizing that people can make crap with any tool you put in their hands, be it Seedance, Houdini, or a typewriter.