Every country is different. I’m in China right now and while there isn’t much rubbish - it is still pretty dirty. Whereas in New Zealand you can walk barefoot all day and your feet will stay clean (matter of fact thats my kids do literally all the time).

Then sanitation itself is a but of a moot. Bacteria can spread million different ways, it’s mostly futile fight. If you wear flip-flops all day and don’t wash your feet, don’t shower after using public bathrooms, etc - whats the point?