Comment by tannhaeuser

While it's true that XML is a generic serialization of angle-bracket markup that doesn't need a schema for serialization (which was exactly the main motivation for its "invention" as a SGML subset), the reason it's being used in inter-party or long-term/loosely-coupled service payload serialization is because it has fairly powerful and well-established schema languages (XML DTDs and XML Schema) for validation. This is unlike JSON which thrives in ad-hoc serialization for tightly-coupled back-ends and web front-ends (and only in that scenario IMHO). So I don't think XML belongs into the "schema-less, copying" category.