Even the original designers of XML (those responsible for subsetting XML from SGML, and those responsible for dropping the ball by adding XML namespaces on top

Even the original designers of XML (those responsible for subsetting XML from SGML, and those responsible for dropping the ball by adding XML namespaces on top ;) aren't happy with it [1]. As to why URIs, I completely agree. I think URIs/URLs were introduced by TBL as arguably the major feat of HTML over generic SGML along with <a> and so phenomenally successful every W3C mechanism of name resolution and namespacing had to make use if it; RDF is littered with namespaces as well. [1]: https://blog.jclark.com/2010/01/xml-namespaces.html https://blog.jclark.com/2010/01/xml-namespaces.html