So, I was wondering when I would see that... from my experience, I would say it also makes mediocre developers bad ones very fast. The reason being a false sense of confidence, but mostly it's because of the sheer volume that is produced.

If we want to be more precise, I think the main issue is that the AI-generated code lacks a clear architecture. It has no (or very little) respect for overall information flow, and single-responsibility principle.

Since the AI wants you to have "safe" code, so it will catch things and return non-results instead. In practice, that means the calling code has to inspect the result to see if it's a placeholder or not, instead of being confident because you'd get an exception otherwise.

Similarly, to avoid problems the AI might tweak some parameter. If for example you were to design an program to process something with AI, you might to gather_parameters -> call -> process_results. Call should not try to do funky things with parameters because that should be fixed at the gathering step. But locally the AI is always going to suggest having a bunch of "if this parameter is not good, swap it silently so that it can go through anyway".

Then tests are such a problem it would require an even longer explanation...