[azemetre]

Only a "threat" because they don't have the tax base to support the infrastructure that is needed so it requires massive federal subsides and they are massively inefficient.

For the entire recorded human history, people have lived in cities just fine.

The problems today are entirely self created and imposed by governments and culture of people.

Take housing, the easiest way to solve the housing crisis in Canada and the US is to build more supply and a variety of housing (boarding homes, multi-family homes, 12-unit condos, mixed housing, giant apartment complexes, studios, micro studios). That would likely alleviate a multitude of problems cities have and probably solve a few others unexpectedly (increasing the tax base, the variety of people that live there, etc).

But walk into any public development meeting you will see a few dozen people force the process to a crawling halt because of a myriad of reasons. The needs of the few now outweigh the good of many.