Namespaces were fun! But mostly used for over engineering formats and interacted with by idiots who do not give a toss. Shout out to every service that would break as soon as elementtree got involved. And my idiot colleagues who work on EDI.

Namespaces are a cool idea that didn't really seem to pan out in practice.

Nope, they were great.

Our AOLServer like clone in 2000 used them to great effect in our widget component library.