Very good points. I have very limited knowledge about the inner workings of most LLMs, I just know the tidbits I've read here and there.
As far as quantum computers, based on my current understanding is once they're at a point where they can be used commercially, they should easily be able to model/run artificial neural networks. Based on the stuff I've seen from Dr. Michio Kaku, quantum computers will eventually have the capacity to do pretty much anything.