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>
    <allusers aufrom="なむりよここなたばく" />
  </query-continue>
  <query>
    <allusers>
      <u userid="409" name="【復活】 コロナの真実 カロリーゼロ 【復活】" />
      <u userid="373" name="あんころ(餅)" />
      <u userid="404" name="うるさいうるさい氏ね氏ね" />
      <u userid="406" name="さかおり" />
      <u userid="382" name="さよなら" />
      <u userid="413" name="さらば地球よ旅立つ船は問題ユーザーNaidepne" />
      <u userid="10" name="しろうさぎ" />
      <u userid="398" name="それでもさかおり" />
      <u userid="376" name="てと" />
      <u userid="23" name="なか" />
    </allusers>
  </query>
</api>