You are looking at the HTML representation of the XML format.
HTML is good for debugging, but is unsuitable for application use.
Specify the format parameter to change the output format.
To see the non HTML representation of the XML format, set format=xml.
See the complete documentation, or API help for more information. 
<?xml version="1.0"?>
<api>
  <query-continue>
    <revisions rvcontinue="17882" />
  </query-continue>
  <query>
    <pages>
      <page pageid="1" ns="0" title="Main Page">
        <revisions>
          <rev user="Rubberkitten" timestamp="2019-01-06T11:29:54Z" comment="Further correction to wanted pages" />
          <rev user="Rubberkitten" timestamp="2019-01-06T11:01:19Z" comment="Overhaul list of wanted pages" />
          <rev user="Catsuit" timestamp="2019-01-04T21:52:04Z" comment="Remove two wanted articles that have now been created" />
          <rev user="Catsuit" timestamp="2019-01-02T17:56:22Z" comment="Update list of wanted articles" />
          <rev user="Gaggedbound" timestamp="2018-12-02T19:04:53Z" comment="Update list of wanted articles" />
        </revisions>
      </page>
    </pages>
  </query>
</api>