I sit to pee at night because it's quiet and a girl lives in the room next to our toilet and i'm conscientious of her room sounding like a piss factory (has mentioned it before that i've woken her up coming home drunk and taking a long piss). Plus i like the feeling of just letting it all relax and flow out when i sit, sometimes i'll decide to poop when i just went in for a piss. Also i'm six foot six, splashback occurs while standing (piss into your bowl standing up wearing nothing breh, your skin will feel the tiny drops) unless i aim perfectly at the slope of the bowl so it slides in before hitting the water (maybe this only affects people of my height?). I get none of that shit while sitting.
Urinals are usually situated higher so the gravity splashback effect does not occur.
In short, it's quieter, cleaner and more comfortable. Sitting down +1