One advanced civilization has tens of thousand of free public toilets.
https://lazyholidayplanner.com/essential-tools/japan-toilet-...
https://www.cnn.com/travel/gallery/japanese-public-toilet-ph...
https://www.toilet-map-jp.com/en
https://toiletrix.org/toilets/japan
https://commons.wikimedia.org/wiki/Category:Public_toilets_i...
Plus, virtually every convenience store in Japan has a clean and ready-to-use bathroom. And there is a very high density of convenience stores. Bathrooms everywhere!