I have my touchbar display the time, battery percentage and current song, so when I look down it's mostly to look at these. I also have a script that displays the last line of a particular file, so if I pipe a script's output in there I can look at its progress. I can swipe anywhere with two fingers to change the volume, three fingers is ctrl+tab (that one isn't useful, I need to figure out a better use), four fingers is brightness. I like it better than the F keys.
I did have to remap Caps Lock to ESC, because ESC on the touchbar was nigh unusable.
BetterTouchTool. It's not free, but it's cheap enough, and it lets you do a lot of cool things (including the multi finger swiping which you can assign to anything you want). You can write AppleScript routines and assign them to buttons, or have them run every n milliseconds to display something, which is what I did for the last line of the file thing.
I did have to remap Caps Lock to ESC, because ESC on the touchbar was nigh unusable.