Many Windows 10 devices have touch screens these days, and some with detachable keyboards (such as Microsoft Surface Pro) or even without keyboard. The original AoE had an option for one-button mice that mostly works for playing with just your touch as mouse clicks, except for scrolling.
Obviously it is not a competitive way of playing the game, but it would be awesome to be able to play the game single-player on the go! I would therefore propose that drag-to-scroll worked for the one-button mode using touch screen.