Genuine question: Why do we need both humans and AI?

I feel this is another thing that proponents state as if it's unchallengeable fact, an all-progress-is-good thing.

I question this assertion. People have become all too comfortable with it.

I don't think teaching needs AI at all, and if it does, a traditional expert system would be better. I think there's a staggering range of opportunities for improving teaching materials that don't involve LLMs, and they are all being ignored because of where the hot money goes.