That may be so, but most opinions I hear in discussions about XML vs JSON say that JSON is more readable, probably because it's less redundant and similar to data structures found in some programming languages.

Really? Let's write a shopping list on a piece of paper in JSON and XML. Which one would be more similar to the way we write down lists in real life?

XML:

   <list>
    <items> 
       <item>Milk</item>
       <item>Eggs</item>
       <item>Bread</item>
       <item>Butter</item>
     </items>
   </list>

JSON:

    {
       "list": {
         "items": [
            "Milk",
            "Eggs",
            "Bread",
            "Butter"
        ]
      }
    }

I don't know that either one is particularly close to the way I'd write down a list in real life, to be honest. This is a pretty trivial sample, and neither is especially hard to read/parse by a human. But the JSON still looks closer to line-noise to me. :-)