...hmm, at some point we'll need to find a new place to draw the boundaries, won't we?
Until ~2022 there was a clear line between human-generated code and computer-generated code. The former was generally optimized for readability and the latter was optimized for speed at all cost.
Now we have computer-generated code in the human layer and it's not obvious what it should be optimized for.
> it's not obvious what it should be optimized for
It should be optimized for readability by AI. If a human wants to know what a given bit of code does, they can just ask.