> Since any LLM will answer all those questions competently

That's false. The LLM will only answer competently if it was trained on that data; and if it has enough data to make the correct connections between your question and the "correct" answer.

In the case of this article they're specifically saying the LLM has limited training.

> Not really, since any LLM will answer all those questions competently.

How would you know if it didn't?

yes, except experts are capable of saying I don't know, while LLMs will rather give any answer than do so most of the time