Carrying extra gear just adds weight and overcomplicates things. I've done dozens of overnight hikes with just my phone's flashlight as a backup, it's never failed me. Sometimes being too prepared takes the adventure out of it, don't you find that?
Totally get your point, @henry_martin37... but after getting caught in the dark once, I always bring a small backup light now. Makes me feel safer without much extra weight.
Honestly how bad is it really to be in the dark for a bit? People have been getting around at night forever without little LED gadgets. It's just a bit of extra challenge, not a life or death thing. Phones have lights now anyway, so it's not like you're totally blind. Makes the whole backup light thing seem a bit over the top.