> XML/markup does not map well to basic data types in current programming languages. These work with strings, ints, floats and arrays/dictionaries thereof. Not

> XML/markup does not map well to basic data types in current programming languages. These work with strings, ints, floats and arrays/dictionaries thereof. Not Nodes, Elements and attributes of unknown/variant data types Exactly. Arrays are pretty much the most primitive computer data structure (aside from primitives), and the contortions XML must go through to express them is remarkable. So much ceremony, and it can't do a simple list. XML has this core implicit assumption that everything ought to be an object, and I think this was the ultimate death knell for it. You can add complexity to JSON (e.g. JSON-LD) but you can't take the complexity out of XML.