[nitwit005]

The AI doesn't know what good or bad code is. It doesn't know what surpassing someone means. It's been trained to generate text similar to its training data, and that's what it does.

If you feed it only good code, we'd expect a better result, but currently we're feeding it average code. The cost to evaluate code quality for the huge data set is too high.

[recursive]

The training data includes plenty of examples of labelled good and bad code. And comparisons between two implementations plus trade-offs and costs and benefits. I think it absolutely does "know" good code, in the sense that it can know anything at all.

[nitwit005]

There does exist some text making comparisons like that, but compared to the raw quantity of totally unlabeled code out there, it's tiny.

You can do some basic checks like "does it actually compile", but for the most part you'd really need to go out and do manual categorization, which would be brutally expensive.