Surprisingly studies have shown not all that bad compared to gas pump nozzles. Most public restrooms get cleaned once in a while.
https://globalnews.ca/news/4231757/toilet-seat-germs/
It’s probably me...i have to use public restrooms a lot...and at least half of them look worse than a condemned outhouse.
coughing/sneezing/spitting and/or..not covering mouth.. not washing hands.. then touching other things about covers most everything....like pump handles and shopping carts..