There's a similar problem with AI-generated video, but it's in the time dimension. There's a huge genre of Asian vertical dramas, and now about 17,000 a day are being cranked out by AI systems. But there are maybe ten major plots. "Lost daughter of rich family comes home" appears over and over. There are longer videos where the plot gets lost. 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.

This probably comes from a lack of intermediate level structure. To make a good dramatic story, you usually start from a plot summary, add character sheets, develop a plot, then a storyboard, then detail the storyboard. That way, you end up at the desired end. If you just let LLM-based systems free run, they go on forever, which is real life but bad entertainment. Unless the goal is a soap opera.

There's good stuff out there, from people who can plot.