I use my device mostly as a camera and a flashlight when I work night shift. I only need the device 4 times during those 8 hours, 2 minutes each time the most (8 minutes total)
Would it make sense to turn the device off after using it or is the amount of battery I’m gonna save negligible?
Another question would be: Would it make sense to turn the device off when I leave the workplace? 16 hours of savings, or would this also be negligible?
To answer the question in the title - it varies a lot. For example one of the things I hate about my (Exynos) S22 Ultra is the high “sleep mode” drain - about 1.5% / hour on Wifi.
At the same time some other phones I have drain like 3% in 24h under the same conditions.
I have yet to find a good pattern what causes good standby times vs bad ones but in general Qualcomm chips perform better than Mediatek Chips which perform better than Exynos chips. And generally speaking ROMs that are close to Stock Android perform better than heavily altered ones.
For optimizations - best thing you can do is turn off Location Services and Bluetooth while you don’t need them. And Airplane mode also helps.
Also I think since the phone “wastes” a lot of energy during bootup its probably better to just put your phone in airplane mode instead of turning it off.