Even if you removed all these single family homes inside city and built skyscrappers instead, the additional units will get filled up pretty soon and at some po

Even if you removed all these single family homes inside city and built skyscrappers instead, the additional units will get filled up pretty soon and at some point not too distant, you will be in the same situation again where you are now. The key fact here is that cities are seeing huge migrations from other areas since last couple of decades. There 100s of thousands of people piling up each year. Eventually they will get saturated. In large scheme of things, cities are artifact of ancient times when transportation was hard and natural landscape for habitat was scarce. Now both problems can be solved even for extreme places such as Dubai and there is no reason for huge swaths for human population to be concentrated in cities.