JoshTriplett parent
Having architecture diagrams is not fundamentally a bad thing, and standardizing the conventions for them is not fundamentally a bad thing. I think the thing that gave UML a terribly bad name was the cavalcade of early "zero code" or "low code" tools trying to turn your UML diagram into code; those were terrible.
Drawing things on whiteboards to see the architecture, absolutely.
The more formalism it has and the more it was insisted on was always a strong signal that was was happening was a middle management cargo cult and not actually useful work.
I believe that there exist organizations that derived value from this sort of thing, I just haven't seen them.