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>
    <allfileusages afcontinue="Enterprise_wikis_wm2011_kaempgen.pdf" />
  </query-continue>
  <query>
    <allfileusages>
      <f ns="6" title="File:Benedikt 2023.jpg" />
      <f ns="6" title="File:Benedikt eHealth Symposium Südwest 2023 - ChatGPT small.jpg" />
      <f ns="6" title="File:Breucker kaempgen harth seo4olap BDSDST 2016 cr 2016-06-27.pdf" />
      <f ns="6" title="File:Breucker kaempgen harth seo4olap praesentation 2016-09-26 v5.pdf" />
      <f ns="6" title="File:CURAC kaempgen maerz et al liver factors pre-final.pdf" />
      <f ns="6" title="File:Catalina bigger 5 runs test including slice 2013-10-22 v4.png" />
      <f ns="6" title="File:Cellset schematically.png" />
      <f ns="6" title="File:Che in-use-paper iswc 2016.pdf" />
      <f ns="6" title="File:Cold2014 GemmekeMPGWKNMR.pdf" />
      <f ns="6" title="File:Ddm kaempgen deris.pdf" />
    </allfileusages>
  </query>
</api>