Every key is written twice, for opening and closing. Keys can be duplicated, and in fact that's what you have to do if you want a simple list. There aren't numeric types, so you have to parse strings. It also looks horrible.

  <cds>
    <cd><title>Led Zeppelin II</title><artist>Led Zeppelin</artist><price>999</price></cd>
    <cd><title>La Brise<title><artist>Arax</artist><price>999</price></cd>
  </cds>

or

  <cds>
    <cd>
      <title>Led Zeppelin II</title>
      <artist>Led Zeppelin</artist>
      <price>999</price>
    </cd>
    <cd>
      <title>La Brise<title>
      <artist>Arax</artist>
      <price>999</price>
    </cd>
  </cds>

vs something like

  [
    {"title": "Led Zeppelin II", "artist": "Led Zeppelin", "price": 999},
    {"title": "La Brise", "artist": "Arax", "price": 999},
  ]

You can probably do better using XML attributes. But then you're using more features.