> So we're doing waterfall again?

I think the big difference between this and waterfall is that waterfall talked about the execution phase before the testing phase, and we have moved past defining the entire system as a completed project before breaking ground. Nothing in defining a feature in documentation up front stops continuous learning and adaptation.

However, LLMs and code breaks the "Working software over comprehensive documentation" component of agile. It breaks because documentation now matters in a way it didn't when working with small teams.

However, it also breaks because writing comprehensive documentation is now cheaper in time than it was three years ago. The big problem now is maintaining that documentation. Nobody is doing a good job of that yet - at least that I've seen.

(Note: I think I have an idea here if there are others interested in tackling this problem.)