EDIT: I changed my argument completely.

That makes no sense because what if you refactor your code ad infinitum using AI? You spin up a working implementation, then read through the code, catalog the changes like interface, docs, code quality and patterns and delegate to the AI to write what you would.

It's 100% AI code and it's 100% human code. That distinction is what's counterproductive.

Because at the end of the day, someone has to own the code, so some lines have to be drawn no matter how arbitrary they seem.