I find massive blobs of XML easier to grok than massive blobs of JSON, esp well-designed XML with namespaces and use of attributes. XML is self documenting.

JSON is just a homogeneous unnamed bunch of braces and key-val pairs that you loose yourself in once you are several MB in and deeply nested. Need to resort to CLI tools like jq or hunt for the schema or docs.

Massive blobs of YAML, well - they should be simply categorized as a war-crime.

Hell, you can parse XML and infer complex types! Good luck doing that with JSON though.