People also like superhero films but they are not exactly lauded as the pinnacle of cinema. I don't think this proves anything about AI being better or equivalent to human writers in terms of style and content - more that broadly appealing works appeal broadly...
I think it maybe not proves, but indicates the efficacy of RLHF mastery and demagoguery, or pandering to the structures humans desire, maybe? These systems are really good at handling humans. They were built on it.