I suspect that traditional urban planning in the USA also assumed that relatively few people would be trying to pack into city centers to work. Because modern office parks hadn't been invented yet, and modern curtain wall skyscrapers hadn't been invented yet, and consolidating many industries into a relatively small number of massive tech companies hadn't happened yet, and the two-income family (which doubles the potential number of commuters per dwelling unit) hadn't become such a thing yet, etc.
There's a part of me that wonders if part of what's going on here is a cadre of genxers who are so wealthy as to necessarily be out-of-touch don't realize that typical millennials' and zoomers' socioeconomic reality is not, and cannot reasonably be forced to be, similar to that of boomers and the greatest generation.
There are a lot of dynamics. Certainly among my grad school class almost no one went to work/live in the city in the late 80s. And, indeed, essentially all tech had migrated out of the city (Boston/Cambridge) by then.
A lot of people did move to Manhattan for finance. But most left after they gained partners and kids.
In general, I suspect a lot of younger/better-educated/wealthier folks have latched onto some of the more elite cities, when they might not have done so in the past, but may not stay there over time.
There's a part of me that wonders if part of what's going on here is a cadre of genxers who are so wealthy as to necessarily be out-of-touch don't realize that typical millennials' and zoomers' socioeconomic reality is not, and cannot reasonably be forced to be, similar to that of boomers and the greatest generation.