Fundamentally it cannot reach the scope or accuracy of a highly skilled person. It's a limitation of how LLMs function.
Not bad for a parrot.
As for language, LLMs showed that we didn't really understand what language was. Don't sell language short as a concept. It does more than we think.
It has not happened yet.
If it does, how trustworthy would it be? What would it be used for?
HAL-9000 (https://en.wikipedia.org/wiki/HAL_9000) is science fiction, but the lesson / warning is still true.