To use global and user settings.xml provided by the Config File Provider plugin, one must declare both files to be used with every single job. This is a lot of work, hence error prone.
It would be smarter if one could simply go to "Manage Jenkins > Configure Jenkins > Maven" and declare the provided settings.xml files to be used there.
Benefit: The jobs do not need to know about any particular settings.xml file. All jobs run with this Maven version will then use that settings.xml files automatically. One could not accidentially forget to configure these files at new jobs.