Can't speak for everyone but in my experience using public toilets (predominantly UK, pubs and train stations):

* there's not always a properly functioning seat / seat at all

* the seat is not always dry

* the cubicles do not always have a functioning lock

* the bowl is not always 'clear'...for reasons probably best left unexplored, people seem to choose public toilets as a place to carry out the most incomprehensible and unimaginable of all bowel movements. I've been greeted with bowls that let's just say would be assessed by a trained professional

Public toilets are also often pretty grim places in general due to the smells, sounds and general lack of hygiene/cleanliness.

All that said...IF the toilets look in decent repair I personally will use the cubicle and sit down, but it's probably less than 30% of toilets that feel like that's an option.

Also just to say I am someone who always sits to pee whenever at home/in a person's home and i'm not someone who anyone would ever call a germaphobe, so I do generally choose to sit rather than stand.

The gents loo at a non-posh UK pub is about the lowest you can go in the western hemisphere.