LLMs suck at creative writing, all their edges get smoothed the fuck out of with RLHF for (brand) safety, so they write like they have a HR lady in the room with them, scrutinizing every sentence for adherence to the set of values very few people honestly hold. if you feed Claude/GPT/Gemini 100 chapters of ASOIAF and prompt it to continue, the story and the prose will degenerate into sterile purple slop within a few pages.