What's kind of funny is that New York always had that "shithole country" vibe for anyone not from there - loud, dirty, crooked, dangerous, overcrowded, largely poor living side-by-side with ostentatious wealth... certainly this isn't new, as it welcomed the teeming masses into ill-designed city structures, yet somehow they evolved to be the powerhouse of the 2nd industrial revolution and the Gay 20's and the postwar boom.
But slums have always been a kind of Petri Dish of humanity where both scum & beautiful patterns rise to the top.
Stewart Brand noted a while ago that cities like Lagos are much more eco-efficient than individual rural living - that the jumble of makeshift resources somehow optimize, just like one famous Economist wrote a tribute analysis of how in an unplanned market economy all the pieces came together to provide him a sandwich vendor outside his Manhattan office with fresh lettuce and tomato.
Europe has kind of turned the city concept a bit bland - it all works well, but it's just not as exciting as these 3rd World centers of chaos. That's good and bad - our future is negentropy, to take the risk & chance out of things, bring about order, even though at the margins there'll always be some danger.
My encounter of the madness of Calcutta (Howrah) train station - so disorienting - not even ticket counters that work like ticket counters (hint: pay off someone to get you a ticket). Bodies lying in the gutters and on the sidewalks - dead? or just napping? most likely the latter... then a chaotic "diner" before catching the train. Of course Calcutta wasn't only the train station - other parts better, others worse - neither did I see - my whole impression based on a few minutes in a train station. So human.