[MonkeyRonin]

One of the big differences likely relates to the regulatory framework of building high-rises.

Getting a tower built in most North American cities typically requires a fairly restrictive process of rezoning, community consultation, and development fees. These tend to be lengthy, expensive, and require a certain level of expertise that usually only larger developers possess. On top of that, height limits are pretty common, but width/depth limits are not.

This changes the economics of construction such that they typically need to involve larger land assemblies to be viable (and/or if you're a developer trying to maximize profit, you can make more by building out rather than up). An owner of a single property wanting to throw up a 12-storey tower on their lot is not really feasible. Where skinny towers do exist they tend to either be high-end boutique developments or legacy developments from a time with less restrictive zoning bylaws.

Just a hunch, but I would guess that the same is not true in São Paulo.