I've seen this with every new version of Windows (except Windows 8.x, which I haven't used and instead jumped from Windows 7 to Windows 10). With each new introduction and addition of polish, you still see old dialogs and methods of doing things underneath once you go one or two levels in. Control Panel is the best example of this. Windows 10 isn't even a complete OS yet. As an example, if I go to Settings and search for "proxy", nothing would show up. If I drill down into Network manually, then I can see and change the proxy settings. I'm sure there are many other unfinished things in it. It's as if they released an in-progress OS right in the middle of a development cycle, and I find it both frustrating to use and ridiculous!