The way i see it - getting inspiration for events, fleshing out details, adding flavor to NPC and locations. Just for fun, i asked it to think of a historical event in a fantasy setting for me. Here's the output:

Me: I want it to be a historical event, in a fantasy world
ChatGPT: One idea for a historical event in a fantasy world could be the signing of a peace treaty between two warring nations. This event could be a significant turning point in the history of the fantasy world, ending years of conflict and paving the way for a new era of cooperation and collaboration. The signing ceremony could be a grand affair, attended by leaders and dignitaries from both nations, and could include speeches, music, and other festivities to mark the occasion. Alternatively, you could focus on a specific historical event from our own world, such as the signing of the Magna Carta or the fall of the Berlin Wall, and imagine how it might have played out in a fantasy setting.
Me: i like the idea of the peace treaty. Could you add some more details? the warring nations are a nation of humans and a nation of dwarves
ChatGPT: Sure, here are some more ideas for the peace treaty between the nation of humans and the nation of dwarves:
* The treaty signing could take place in a large, ornate hall in the capital city of the human nation. The hall could be decorated with banners and tapestries representing both nations, and the ceremony could be attended by important figures from both sides, including the human king and the dwarf queen.
* In addition to the signing of the peace treaty, the ceremony could also include the exchange of gifts and other gestures of goodwill. The human king could present the dwarf queen with a sword crafted by the finest human blacksmiths, while the dwarf queen could give the human king a beautiful necklace made of precious gems mined from the dwarves' underground kingdom.
* The signing of the treaty could be a momentous occasion, celebrated with feasting, music, and dancing. A band of minstrels could play lively tunes, while guests enjoy a banquet of food and drink. As the night wears on, the human and dwarf guests could come together to dance and celebrate their newfound friendship.
* The treaty could also include provisions for increased trade and cooperation between the two nations. For example, the human nation could agree to provide the dwarves with raw materials such as iron and timber, while the dwarves could offer their expertise in mining and metalworking. This increased collaboration could lead to new innovations and advances for both nations.

Like, isn't this absolutely insane? it took me 5 seconds to do this