Personally, auto brightness can't get dim enough at night, and indoors during the day it's annoying seeing the brightness shift everytime the lighting changes even a little. It's great if you're in the sun tho, it can go brighter than the manually set "max" brightness.
OMFG my fiancee refuses to turn down the brightness on her phone at night. Nothing like trying to sleep a foot away from a giant freaking lightbulb.
why not just leave it at auto?
both Samsung and apple have surprisingly good auto brightness! (even budget phones without a physical sensor)
Personally, auto brightness can't get dim enough at night, and indoors during the day it's annoying seeing the brightness shift everytime the lighting changes even a little. It's great if you're in the sun tho, it can go brighter than the manually set "max" brightness.
try out Dimmer on F-Droid if you haven't already for the nighttime issue