I'm not sure what advantage the lights would have over the indicating handle.
In a panelboard there would be so many lights in it that you would have to walk right up close to see which light was which. Once you got that close it would be just as easy to look at the handle position.
Although I did have a rather odd request from a paperpusher at the Chicago Park District that wanted me to provide a pilot light that would go on when they lost power and go off when the power came back on.
LOL
