Fictional content can be "dry" if you give it a simple prompt like "Generate a story about some kids going on a treasure hunt." I've found though that if you put a lot of details in the prompt about what you want in the story and request ChatGPT include sensory details in the prose the quality of the content is much better.
Because of OpenAI's content policy generating horror stories or a creepypasta about Jeff the Killer is virtually impossible without a jailbreak prompt. Even when using a jailbreak prompt sometimes the text stops being generated mid-way though the story and the text turns red with an error message.
ChatGPT gets really confused with certain fictional tropes like time travel and characters switching bodies. Hopefully in a few years ChatGPT can handle those kinds of higher cognitive details better.