I’d put money on the average developer being significantly worse at writing code with bugs than an AI.

I'd take that bet if it was measured in "bugs per day" instead of "bugs per LOC". LLMs generate far fewer bugs in absolute terms, but they also generate far more code, so it probably balances out if everything is equal. I think LLMs will actually lead to more bugs just because they're usually working with poorly defined requirements (prompts) and they guess to fill in the gaps based on the averages of their training data. A lot of those guesses are wrong.

Where LLMs win though is the severity. An LLM will write buggy code in the sense that it doesn't do what you wanted it, but not so much in the sense of security or data loss bugs. They get that right more than humans because they're trained to care about that stuff. There's far more "how to write good code" content in the training data than "how to not care about security and go fast" content (because writing that would be weird!)

You’d take the bet if you could completely choose a different set of parameters? At no point did I say every line of a vibe-coded project in its entirety is better than every line of every repository created by humans, or anything of the sort.

You also go on to admit that the direct quality of the code is likely to better when written by AI — exactly the basis of what I argued — but wish to disagree with what I argued? An interesting position that I don’t quite follow.

The point was that using “human” as an indicator of “code quality” is nonsense. I get CB reasoning for disallowing “vibe-coded” apps when talking about the junk that people are constantly updating/building/deploying for an audience of none, wasting resources. Totally sensible from that perspective, but it takes a baby with the bath water approach that all vibe-coding is bad. I’m simply saying the point of view “if AI then bad, if human then good” isn’t grounded in reality and that your average developer is not producing high quality, well structured, well organized, well documented code. On average, it could be even odds as to whether that developer primarily works on Wordpress.