They produce good code when I'm personally reviewing them. There are a few other people who work with who likewise know how to review code and thus can get good code out of an LLM. There are, however, a lot of people who just accept the first slop that they get out of it and that's not good code.

The larger issue of good code isn't the actual individual lines, it's the overall architecture. And that's what I'm going to be reviewing first is, is this a good approach? Then the interfaces to other code is this a good interface. Get those two right and we can go back for the details. In a lot of cases, the LLM is plenty good at those details.

In some cases, an LLM is better than what I could do. Well, I suppose I can trace down all the locks in all the different special cases, and I have done that, but that was a huge amount of effort that I really don't want to repeat.

Note that I'm talking about recent models. If you're asking about the models of just one year ago, I would give a very different answer about the type of code an LLM produces.