As for South America it all depend on the country and city.
For example if you want Buenos Aires you can use Paris with English train and subway and if you want you can add some Italian monuments and statues.
Old buildings, one century or more, in general have Spanish or Portuguese architecture and modern buildings are modern buildings as any modern building in any part of the world.
All is made with masonery, wood is not used at all.
A combination of Spanish, French and Italian buildings will work fine.
As for misery and miserable people that exist in many countries and cities, there's no architecture at all and it makes no difference if you are in Rio de Janeiro or South Africa, it all look the same.

Stupidity also evolves!