People really want a GUIs that are much more dynamic and context-aware. The size of the buttons should change if I attach a mouse or a touchpad. The on-screen-keyboard should completely disable itself if I attach a keyboard. (Did Windows figure this out yet?) If I walk into a dark room, apps (and ideally, websites) should change to dark mode. If I walk into an area with direct sunlight, the contrast should be boosted. The device should behave differently if it's laying flat on a desk, or on a kickstand, or if I'm holding it in my hands.

Cell phones are better. They've figured out obvious things like screen rotation, adaptive brightness, bluetooth audio handoffs, and Android has made some headway with things like darkmode and automatically changing settings when you get into a car, but tablets have lagged behind, and I'm sure there are dozens more tiny things that automatically changed based on the device's context.