Not sure what you were getting at with this question. You're implying wasteful? 40 or 100 LEDs of appropriate indicator brightness would be about 5 watts max.
Wouldn't they be nice in a dim or dark room? I'd put in 3 LEDs... green ON, red tripped, blue OFF (so that no light at all would mean trouble)
Ida know. I'm a bit old fashion. I rarely trip breakers, I'm standing in front of the panel anyways so I just look. Even with the flag on the QO or the handle is in the middle or put 50 LEDs on it, I'm gonna test it with my meter anyhow.
Years ago there was a brand called "Trip & Light" or something similar, they seemed to be based on a ITE/Siemens breaker, but have not seen them in years, guess they never caught on.