No, I think that's true only in theory. It's true only in the hypothetical. It's only true when you're literally authoring the markup languages and no tools exists yet.
In the vast majority of cases, XML, like YAML or JSON, is machine written and machine parsed. Further, there's an almost unlimited number of tools available for manipulation. That's why nobody makes markup languages like SGML anymore unless they have to.
Heck, there's LaTeX, a document markup language which the HN users themselves seem to insist is incredibly easy to write in a text editor by hand, and that doesn't have verbose closing tags. Nevermind programming languages, etc.
No, SGML and it's descendants are weird in their insistence that structures must be as verbose as possible.
