I've used and use several different illuminated scopes, from cheap to high $. Never had the electronics give up the ghost but have seen dead batteries.
Illumination can be nice in low light if it's a small area with extremely dim settings....can ruin low light view if it's to bright or to much is illuminated. Daylight bright like the NX8 1-8 is very nice for quick shooting....sucks in low light. Pros and cons to everything. I think S&B's FlashDot is really nice in low light as well as their P3 illuminated inner plex.
I understand the OP's questioning. The more complicated something is the more chances it has to fail. I hate to rely on illumination. For a hunting scope I much prefer bold outer posts no more than 5 mils from the center...prefer 3.5 mils....measured tick on windage holds, with a fine center. Bracket in low light, don't have to hunt for it in sun/shadows or tangled backgrounds, and the inner plex is still fine enough for precision.
