I've been convinced of the necessity of lights and powered optics for night use from a couple of instances;
1. The bear trying to snack on the chickens, battery in elcan was dead so couldn't see the reticle, hit the streamlight rm1 and then the etched reticle worked. The light alone scared the bear off.
2. The coyotes and the same chickens, had a dot on this time, and the light gave me info on background for shooting so I didn't launch shit into neighbors, shed, barn, cars ect.
3. Night time ATV trespassers, the light told them everything they needed to know, they promptly left in a hurry.
I have been using streamlights for a long time, and I've yet to break one or have one die, 2 years ago I swapped lamps in my old m3 and m5 with led bulbs to get them into modern times. I can say the lumen/candela wars are overrated. I have a 1k lumen on my handgun, and 300-500 on rifles and they all do the job.
At this point all my serious rifles have a sling, a light and a powered optic be it tridium or battery.