Urban environments have more people. Because those people are prone to taking public transit, meaning they’re carrying possessions with them, they’re more likely to have trash. If there’s nowhere to put it, they’ll litter.
Yes, a concentration of people in an area is a good reason to keep it clean. We’ve done a very good job at it, as compared to 100 years ago. Municipal sanitation departments are usually underfunded/understaffed.
DOGE sure doesn’t help!
https://x.com/reichlinmelnick/status/1960723486348853326?s=46&t=RLsRhQJBb5vROsgfJWkwSw