The Reagan White House moved to lower tax rates for developers in the 1980s and then years of low interest rates glutted downtowns with office buildings. Time's up.
But high density residential operates to radically different specs. Proper fire escape routes accessible from each dwelling, at least one or more exterior windows to the outdoors per dwelling, individualized electricity and other utilities, and various other considerations. Retrofitting the electricity to get every unit on its own metered connection is a beast of a task by itself. You also have to account for the plumbing being used not only for the toilets/sinks, but also showers, baths, cooking, and junk getting dumped down the pipes in every unit.
But high density residential operates to radically different specs. Proper fire escape routes accessible from each dwelling, at least one or more exterior windows to the outdoors per dwelling, individualized electricity and other utilities, and various other considerations. Retrofitting the electricity to get every unit on its own metered connection is a beast of a task by itself. You also have to account for the plumbing being used not only for the toilets/sinks, but also showers, baths, cooking, and junk getting dumped down the pipes in every unit.