Would it not be based on how he uses it? If they are realistic, it will be mostly like a calculator, right?
Yes, your hand calc speed may decrease a bit because you are not using it all the time, but overall the calculator saves you time and helps you calculate more things.

Would it not be like that in the hands of folk who need it to have proper results?

But yes, A lot of regular LLM output seems iffy and superficial.