This is particularly frustrating, yes. I think I'd actually prefer it if applications could not make arbitrary changes to system/user defaults on their own. I've had problems with this on Windows, when I've needed to use it, but also on Android, and even desktop Linux (Chromium in Debian sid currently, rather bafflingly, seems to make itself the xdg-open default even with $BROWSER, Gnome's default browser setting, and x-www-browser all set to Firefox).

But to ostensibly create central, user-controlled methods and restrictions for setting defaults to prevent unwanted default changes and hijacking, and then actually use that space as an advertisement for your own products (Are you sure you want to change away from Edge? Have you tried Edge? Do you want to switch back to Edge? Microsoft recommends Edge!), while exempting your products from the restrictions, completely destroys the point of those controls, and any respect people would have for it.