> And if you truly believe it made something up, prove it.

You seem to be assuming that the issue is around factual correctness, and that may be the case but the evidence we have so far doesn't support jumping to such a narrow cause.

Is the poor performance because the LLMs are frequently wrong? Unknown.

Is it because the LLMs are sycophantic? Unknown.

Is it because the chat interface is a poor one for learning? Unknown.

What we do know is that students who rely on LLMs learn less and perform worse in the long term. And that alone is enough evidence to support a ban. If better tools come along in the future and are shown to aid learning, then the ban can be re-evaluated.