> A few generations ago inner cities were too dense, filthy, undrivable and morally corrupt to allow civilisation to flourish.

Wrong, due to an specific Anglo-American cultural meme. Civilization has flourished in cities as long as there has been civilization. In the U.S. (uniquely), we ruined cities post WW2 by subsidizing highways and cars and low density suburban mortgages, due to said cultural fetish. Plus a whole lot of racism.

In France, to my knowledge, there was never a time when the central city was considered lower class than the suburbs (ahem, Paris, ahem). And I think this is generally true.