Swiping and zooming a map on a phone or tablet is quicker and far more intuitive than clicking and dragging with a mouse. You can't scroll to a precise depth without moving your mouse to a specific UI slider. Whereas with touch you control it with the spread of your fingers.

One big piece of functionality missing from mouse-controlled maps is rotation. I can't imagine doing it with a mouse, but "grabbing" a map with two fingers and intuitively rotating it to the angle you want is huge.

Similarly, two-finger swipe up/down to adjust viewing angle is something that could technically be done with a slider you drag with a mouse, but I definitely wouldn't call that better.