New ideas come from linking existing ideas and concepts together. That process is called idea synthesis — combining fragments until something new emerges.
The Brainstorm flow is turtles all the way down: each idea you capture can become a trigger for the next. Saved prompts feed back into new combinations, so one note leads to another layer of possibilities.
AIs like ChatGPT are likely to give you existing ideas that have already been formed. Brainstorm helps you create new ones by mixing prompts, categories, and concepts in unexpected ways.