Some of the code bases I have at work are legacy spaghetti -- hard to reason about. I too employ the prompt and pray strategy and then see if CI fails. I can only be surgical where I already have a grasp on the codebase, or if I was involved from the beginning.

Morally, I dislike what AI is doing to the profession. Rigor is suffering.

It's also possible to point the AI at legacy spaghetti and say "document this in detail" as a starting point for unspaghettifying it.