The code is only a projection of someone's mental model, which is what actually allows the project to succeed, especially in the long term.

That's why codebases die when they lose maintainers and forks often don't make it past the first few months.

LLM-generated code might work, but it's not backed by anyone's mental model. And the industry has had a long running term for code which is there but no-one understands it nor the reason behind it: legacy code.