I worked on Windows back in 2014, probably the most surprising thing joining there out of college was looking through the bug database. Every issue that gets complained about online -- and many more -- are in there, and have been for a long time, marked WONTFIX due to a potential compatibility break, lack of priority, or some other policy reason. I don't know if anyone even owned Notepad or any other older inbox apps…
My app is even part of their compatibility test suite (they asked me for permission and a license).
I understand the need to move forward and that BW compatibility can be hinder that, but it's really frustrating for me to 1) respond to thousands of people asking why it doesn't work after they upgrade, and 2) lose income because there's nothing I can do to make it work the same in Windows 11.