[bluGill]

Population is expanding in many US cities faster than they are building houses. With houses we need to build schools, stores, parks, offices, and a long list of other things that an expanding population will use more of.

Old infrastructure wears out, and often it fails to meet modern standards and should be replaced (ex old houses often cannot be insulated to modern standards, old bridges we now realize were not built strong enough). Many have for various reasons concluded that some of what we have built in the past was a mistake and so we should tear some things down to replace with something else. (ex replace highways with mass transit)

While we don't need to build or rebuild everything we did in the past, there is still a lot of things that if we would build our life would be better.