XML can be programmable. You can make <If> and <Loop> constructs if you so desired while being trivially parse-able.
XML can be arbitrarily strongly typed.
JSON really was a step backwards in many ways. I think the main reason JSON took over was that it looks nicer and is easier to type by hand (as if everyone doesn't have editor macros for XML).
Really?
Depends on how it’s structured, but I’d say XML is much more READABLE than JSON, although it requires much more typing to write by hand.
And it was a much more rigorous data format than JSON for many years before any of the more modern things like JSON schemas came about.