[Atomskun]

You are cherry-picking the best experience one can have on macOS, and contrasting it with the worst experience on Windows. This way it just sounds like comparing in bad faith.

There is plenty of Mac software that requires an installer and Uninstaller, plenty of off-behaving applications that put stuff directly into ~ or ~/Documents, and even those that install some internal executables into /usr/local/bin.

You can have an equally pleasant experience on Windows (after all, this is about portable apps...). There is "mature" software whose installers will just override (update) the existing application (e.g. Anki, Affinity apps), %APPDATA% is your Application Support folder on Windows (if only more software would use it), and then there's also the slightly new .appx packaging with a clean way of uninstalling. No one hinders you to just download portable apps directly from the vendor and putting it into C:/Applications, if you want that.

If there is an odd one out, it would be Desktop Linux.