This is a task that humans are exceptionally bad at, because we are not computers. If something uses the right words in the right order such that it communicates the correct algorithm to a human, then a human is likely to say "yup, that's correct", even if an hour's study of these 15 lines reveals that a subtle punctuation choice, or a subtle mismatch between a function's name and its semantics, would reveal that it implements a different algorithm to the expected one.

LLMs do not understand prose or code in the same way humans do (such that "understand" is misleading terminology), but they understand them in a way that's way closer to fuzzy natural language interpretation than pedantic programming language interpretation. (An LLM will be confused if you rename all the variables: a compiler won't even notice.)

So we've built a machine that makes the kinds of mistakes that humans struggle to spot, used RLHF to optimise it for persuasiveness, and now we're expecting humans to do a good job reviewing its output. And, per Kernighan's law:

> Everyone knows that debugging is twice as hard as writing a program in the first place. So if you're as clever as you can be when you write it, how will you ever debug it?

And that's the ideal situation where you're the one who's written it: reading other people's code is generally harder than reading your own. So how do you expect to fare when you're reading nobody's code at all?