A knife's function is deterministic. LLMs are not.
They routinely misinterpret the information they've ingested and confidently spit out incorrect statements. Worse - they confidently spit out incorrect statements in ways we cannot anticipate.
This isn't comparable to a person. This isn't comparable to human intelligence. This isn't a problem that can be handwaved away by saying "people are sometimes wrong too!"
LLMs are like a knife. It is a tool that can hurt you if you misuse it, but it also has the capability to save LOTS to time if you use it well.