Making scrubbers for audio/video (more) physical is nice, since scrubbing video with a mouse usually requires that you first move the mouse to wherever the video player puts its scrubber, and scrubbing with the keyboard usually requires multi-key combos and always has the “wrong” granularity. (It’s also helpful in that you can now combine this scrubbing in a gesture with mouse movement, e.g. picking up a clip from your library in iMovie, scrubbing through the timeline to scroll it to the right position, and then moving the mouse over to the timeline and dropping it. That’s basically an impossible gesture with mouse-movements alone; you’re left to hover the clip over the scroll-edge of the timeline and wait for it to accelerate its scrolling [and then usually overshoot].)
Come to think of it, Sublime Text and other IDEs with a minimap could display it (rotated to horizontal) on the touch-bar, and let you scrub on it, too. Do they?