There's a reason Apple separated iOS and macOS, and that no one ships desktops with Android: touch and traditional WIMP are entirely different interface paradigms, and need very different HIGs. Windows' touch controls feel pasted on instead of organic. Ever try to use any of the Office apps solely with a touchscreen? It's like trying to type with boxing gloves: you get menus nested in menus just to to simple things. Try to use the Control Panel without a keyboard and mouse without screaming. Even the size of the window controls is way too big for WIMP, but they have to be that large for touch.
Which brings us to number two: Windows still feels like it was designed by committee. There are two different places to change system settings, Settings and the Control Panel. There are three different window management shortcuts, all of which work in different ways, and the most useful (Task View) can't be bound to a mouse button. There's no native text editor in Powershell. I had to transfer a .cfg file to my Mac and edit it in pico, because using Notepad kept messing up the formatting. There's no user feedback when launching an application. Has it crashed? Is it just taking a long time? I dunno.
And on and on.
I like Windows 10, but to argue that it's better than macOS just because it can do more things is, IMO, silly. A Swiss Army knife can do more than my chef's knife, but I know which one I use to make dinner. In terms of usability I'd put Windows third, after macOS and a good Gnome Linux distro.