> Whenever a new app for a given filetype is added, Windows asks you which one you want to use....While Edge getting a special category at the top is annoying, this showcases the uphill battle Microsoft faces, where they get blamed for the actions of other software and user stupidity on a regular basis, because people don't understand how Windows works, in general.
Edge getting a special category at the top is central to the problem. If Firefox 80 added a PDF reader and Windows is being so nice as to let you choose whether you want to use it instead of whatever you currently use, then in the list of PDF reader applications, a user should see it at the top (which will invite them to think "Hey cool, Firefox can now be used for PDFs!") so they are given a choice of sticking with their current thing, or choosing the shiny new capability that was just added.
If you force Edge to the top of your app preference screens, users are obviously going to see the update and go "Yep, that's Microsoft trying to force their crap on me again". Microsoft's well known behavior of forcing updates on the user has already given it a bad reputation in this regard, and has resulted in court cases in the past.
So yeah, it's not "user stupidity", it's the stupidity of whoever made the decision to promote Edge by shoving it in users' faces all the time including filetype handler updates.