I've spent a good amount of time in my career reading high quality code and slop. The difference is not some level of intelligence that sonnet does not possess. It's a well thought out design, good naming, and rigor. Sonnet is as good if not better than the average dev at most of this and with a some good prompting and a little editing can write code as good as most high quality open source projects.
Which is usually far higher than most commerical apps the vast majority of us devs work on.
> with a some good prompting and a little editing can write code good
I agree with a good developer "baby-sitting" the model it's capable of producing good code. Although this is more because the developer is skilled at producing good code so they can tell an AI where it should refactor and how (or they can just do it themselves). If you've spent significant time refitting AI code, it's not really AI code anymore its yours.
Blindly following an AI's lead is where the problem is and this is where bad to mediocre developers get stuck using an AI since the effort/skill required to take the AI off its path and get something good out is largely not practised. This is because they don't have to fix their own code, and what the AI spits out is largely functional - why would anyone spend time thinking about a solution that works that they don't understand how they arrived at?
I've spent soo much time in my life reviewing bad or mediocre code from mediocre devs and 95% of the time the code sonnet 3.5 generates is at least as correct and 99% of the time more legible than what a mediocre dev generates.
It's well commented, the naming is great it rarely tries to get overly clever, it usually does some amount of error handling, it'll at least try to read the documentation, it finds most of the edge cases.
It's easy to forget one major problem with this: we all have been mediocre devs at some point in our lives -- and there will always be times when we're mediocre, even with all our experience, because we can't be experienced in everything.
If these tools replace mediocre devs, leaving only the great devs to produce the code, what are we going to do when the great devs of today age out, and there's no one to replace them with, because all those mediocre devs went on to do something else, instead of hone their craft until they became great devs?
Or maybe we'll luck out, and by the time that happens, our AIs will be good enough that they can program everything, and do it even better than the best of us.
If you can call that "lucking out" -- some of us might disagree.
Which is usually far higher than most commerical apps the vast majority of us devs work on.