I don't disagree about the probability, but the current frontier models are not completely useless for writing even in areas where I have significant knowledge. I would not have said that a year ago. You have to watch them like a hawk -- they are good at spitting out plausible sounding nonsense that is hard even for an expert to discern. But the dice roll going on behind the scenes is continually more biased towards being correct/useful than not.

On factual things, potentially. But if I want to read your writing, wouldn't I be trying to pick your brain? Otherwise why don't I read wikipedia or usage documentation?