I work in land development, so I tend to pay attention to these sorts of things.
I don’t think the suburbs are dying...I think of it more as concentric rings around the city. When the first ring becomes old, the streets fall apart, the neighbors become lousy, etc, people who can leave do just that - and move to a secondary ring.
Sure there are some cities where people are moving back downtown - but that model really only applies to congested areas (northeast), where geography prevents expanding rings.
Look at Detroit as a model. Downtown there are of course the glistening office buildings, stadiums, and all the trappings of a modern city - because this is where people still primarily work. Then there is a broad ring of complete dilapidation - from Google maps its easy to identify these areas, because so many of the houses have been torn down. But further out, just a 15 minute drive by interstate, there are fantastic suburbs, with solid home values and perfectly cut lawns.
I don’t think the suburbs will ever go away, unless something is done to address the underlying urban problems that people are trying to escape from.
True, but it can also work the other way. Overbuild miles outside the city and you could have trouble finding buyers and that leads to decay as well.
Plus, it can be hard to tell where the city ends and the suburbs begin. Some "inner suburbs" have the advantages people are looking for from the city, lower taxes than the city, and a lot of wealthy residents. I don't think they'll just roll over and play dead.