Why? My SO has a Windows laptop with touchscreen, touchpad, keyboard and mouse. She uses the mouse but sometimes pushing a button by touching the screen saves time. If you think about it, by the time you reached for the mouse and started aiming for the button you already pressed it with your finger. The touchpad reduces the travel of the hand but not the time to aim. Hitting something with a finger is always faster. She is missing that on her work laptop.

I used touch on Windows to test multitouch and pen input support in a familiar environment. Less hassle than grabbing a tablet, setting up remote DevTools, etc.