Never owned a Mac but I have just bought a LG V20 phone which has a second always on screen that looks like the touch bar. On a phone it is actually very useful, for instance having the last five apps you opened readily accessible is excellent, it brings the alt-tab power to your mobile. Also I use the flashlight often and it's just right there. Maybe, probably it's a bad idea on a laptop, but having another screen that apps cannot fight for above the main screen on a smartphone or phablet is great.