That doesn't do justice to either waterfall or agile.

Oh certainly - I'm conflating the adjective of agile with the manifesto of agile. I've been on projects with multi-hundred page design docs and multi-week UATs. And nobody wants to go back to prince2 for example.

The point I was trying to make is we should be diving back into the older methodologies and accumulated wisdom and re-evaluate some of the older dead ends with new context.