It's more complicated than a calculator. Even researchers who have dedicated their lives to the field don't know all of the limitations of any given model. That fact alone isn't helpful when a model is 80% correct in one area but 2% in another.

If even experts in the field don’t know all of the limitations then it’s even more important to stress that relying on the output of an LLM is a poor choice without additional checking and verification.

Even with calculators, I was taught that you should double check by hand sometimes to make sure you got it right.