Except that it does not work well as a touch-oriented mobile UI either.
The first time you need to do something remotely advanced it launches a dialog designed for mouse and keyboard, where everything is very small and hard to tap.
Let's say that you want to do something as basic as open a file in the touch-oriented Reader app, then you are forced to use the regular mouse-and-keyboard oriented file dialog.
Need to disable background downloading on the very limited hotel Wifi or Wifi from a tethered phone? Then you need to get into the mouse-and-keyboard oriented Control Panel.
Move or copy a file? The regular file manager. Good luck trying to select more than one file at once: there are gestures for it, but the gesture recognition is very finicky.
Try to tap a link in the web browser? No, half the times Edge thinks that you want to highlight a word in the link.
And so on
If my tablet did not stylus support, it would have driven me crazy.
And oh yes.. You'd better not have a high-DPI screen because apps to be written for it if the UI is not going to be minuscule.