This is neither here nor there. For the most part, new construction has always targeted the middle or upper class, with the less fortunate living in older, depreciated construction from decades past. It's why mature cities have mansions converted into apartments and newer, massive suburban enclaves on the parameter of the city.
It's not until the land is completely used that cities turn to revitalizing their core. But even then, new construction favors the upper class. If you're going to tear down a bunch of old bungalows, they need to be replaced with something pretty expensive to make the project economically viable.
Again, take a look at the remaining older homes in your area. It's not depreciation that makes them cheap. They are very small and poorly, cheaply built by modern standards. Saying they were originally targeted to the middle and upper class says a lot about how the standard of living has improved.
> they need to be replaced with something pretty expensive to make the project economically viable.
Which implicitly requires there being lots and lots and lots of people who can buy them.
It's not until the land is completely used that cities turn to revitalizing their core. But even then, new construction favors the upper class. If you're going to tear down a bunch of old bungalows, they need to be replaced with something pretty expensive to make the project economically viable.