> You have no idea if the alternative code you would have written would have been idiomatic or had some critical flaw.

But I have a feeling for both, which is one of the key components of the skill in our trade.

For idionmatic code, I know the degree to which I'm following how things "should" be done or are "usually" done in a given language. If I'm uncertain, I know that. GPT won't tell me this. Worse, it will confidently claim things, possibly even if presented with evidence to the contrary.

For critical flaws, I know the "dark corners" of the code. Cases which were not obvious to handle or required some trick, etc. I'll test those specifically. With GPTs code, I have no idea what the critical cases are. I can read the code and can try to guess. But it's like outsourcing writing tests to a QA department. Never donna be as effective as the original author of the code. And if I can't trust GPT to write correct code, I can't trust it to write a good test for the code. So, neither the original author of the code (GPT) nor somebody external (me) will be able to test the result properly