The use case that matters for me is: when I'm using them as laptops. Most of the time, my Windows laptops are connected like desktop machines: external monitors, mouse, keyboard. When I take my devices off the desk and go to a cafe or my living room, I use the touchscreen all the time. I don't reach for my mouse to click a button when I have a finger to do it. I probably don't go more than two minutes without touching the screen in that scenario, even while writing code. Scroll up/down is much easier with a finger. Pinch-to-zoom is obviously easier.