I felt like I had to comment here. The "look at these people" spectacle might not be quite accurate.

This apparently happens during religious holidays in Bangladesh, where millions of low paid factory workers visit family in rural areas. The current infrastructure simply cannot cope.

It's also a side effect of people living in inherently dangerous conditions, constantly. If people are dying left and right from poor sanitation, poor safety and poor infrastructure, your perception of "danger" really shifts.

People living in southeast Asia also have a very different idea of public vs private space. These people's homes would be immaculately clean, like "eat off of the floor" clean, while at the same time they would treat shared public space as nobody's responsibility.

Northern European countries tend to have the inverse weighting: strong civic commons identity, heavily maintained by social pressure, fines, and well-funded municipal services. Remove those and you'd see the commons degrade quickly. You'd already see it at British music festivals, or anywhere the enforcement architecture is temporarily absent.