That makes sense, but sometimes it's even more confusing than that!

When I lived in Philadelphia here in the USA, it would vary street by street and block by block even when there were no ethnic or economic divides.

One block would have litter all over the place and the next one would be clean. To this day, I am still puzzled by that.

There are some very mundane possible explanations, probably due to a combination of pedestrian traffic patterns and wind. (My observation is that some % of litter, probably a large % IMO, is simply trash that blew out of trashcans as opposed to being intentionally discarded)

Still, I found it baffling and surprising