How often do you need to measure the approximate voltage of something? Seems to me like a fun gimmick but ultimately not all that useful. the resolution of two

How often do you need to measure the approximate voltage of something? Seems to me like a fun gimmick but ultimately not all that useful. the resolution of two colored LEDs would probably have you second guessing what it's telling you every time you do try to seriously use it, and the actual way you're supposed to use it is kind of dodgy and inconvenient, putting an almost all metal object between the two poles of the thing you're measuring.