@F91G this question is for you, is disabling graphic cards backlight add any meaning to watt consumption I mean those lights can even take up to 10watt combine maybe I'm wrong but I've never disabled my GPU backlight since u bought them.
5 watts per hour, 120 watts per day, 43.2 kilowatts per year
One of the famous sayings of the great inventor Benjamin Franklin was
“A penny saved is a penny earned.” If you are not using it as an emergency lighting, it is best to turn it off.