Using LLMs for ingame characters has been suggested, but is also a bad idea. LLMs are also neural networks, and are thus also never reliable.
Though I guess we have all suffered to the incoherent babbling that Laezel has in later chapters of BG3, where she just forgets what she had said before, and LLMs wouldnt be any worse.
Personally I still would strongly prefer human written interaction. I had my share of experiences with AI now and I am not amused. I would rather take the human written dialogue, thank you very much.