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>
    <allpages gapcontinue="あきれてものも言えねえぜ！" />
  </query-continue>
  <query>
    <pages>
      <page pageid="4078" ns="0" title="Twitter 裏垢" contentmodel="wikitext" pagelanguage="ja" touched="2020-12-11T08:15:53Z" lastrevid="66868" counter="1306" length="0" />
      <page pageid="4042" ns="0" title="VS.こち亀 こちら葛飾区亀有公園前派出所ノベライズアンソロジー" contentmodel="wikitext" pagelanguage="ja" touched="2021-11-05T01:51:34Z" lastrevid="66406" counter="4088" length="1503" new="" />
      <page pageid="4077" ns="0" title="YouTube MP4" contentmodel="wikitext" pagelanguage="ja" touched="2020-11-19T11:25:27Z" lastrevid="66863" counter="2210" length="0" />
      <page pageid="146" ns="0" title="あいつがそいつでこいつがそれで" contentmodel="wikitext" pagelanguage="ja" touched="2021-11-05T01:51:34Z" lastrevid="65810" counter="70797" length="19580" />
    </pages>
  </query>
</api>