Using natural language to specify and build an application is not unlike having a game design document before you actually start prototyping your game. But once you have implemented the bulk of what you wanted, the implementation becomes the reference and you usually end up throwing away the GDD since it's now out of sync with the actual game.

Insisting that for every change one should go read the GDD, implement the feature and then sync back the GDD is cumbersome and doesn't work well in practice. I've never seen that happen.

But if there ever comes a time when some AI/LLM can code the next version of Linux or Windows from scratch based on some series of prompts, then all bets are off. Right now it's clearly not there yet, if ever.