It's not actually the extreme punishments, it's the consistent small punishments. It's that you'll actually, seriously get a ticket for littering, even if it's a relatively small ticket. The "Fine City" enforces it's vision in a ubiquitous way, so people just don't break the rules.

This seems like the most effective solution. Imagine if you knew that if you littered, there is a 100% chance you would get a $10 fine immediately. Almost no one would litter ever again, even though the fine is much smaller than the fine is in most countries.

Problem is it just takes a lot of resources to police, more than the fine revenue. But with CCTV and computer vision it's getting increasingly cheap.

The failings of the broken windows theory[1] would strongly disagree.

[1]: https://en.wikipedia.org/wiki/Broken_windows_theory?wprov=sf...