Ward Cunningham [edit: oops, it was Kent Beck] had it right, long ago, when he wrote in "Extreme Programming" [paraphrase]: You don't drive to Florida by carefully lining up your car in New York on I-95 South, locking the steering wheel, and then pressing the accelerator until you arrive.

This was really all that Agile was ever trying to avoid -- the tyranny of imaginedf omniscience. The bad old way (which I did labor under in the '90s) set up a Gant chart of dependent requirement up front, during a "design phase" which completely de-valued learnings and insights gained along the way as a software system was constructed during the "implementation phase". It was the best we had till then, but many software projects were failing due to their inability to adapt to unforeseen design flaws or to the feedback of stakeholders (once the software finally got into their hands).

I don't know why the ceremonies became ossified and sacred. I guess every movement must confront the danger of settling for form over substance. I do know one thing. You can't build an amazon dot com, a Facebook, or a Grand Theft Auto in a 1-million token context session with an LLM. I'm sure you can do it with many such sessions, but it won't be an LLM that ties it all together properly (again - too much context). And I say this as an enthusiastic user of agentic programming.