The top five also have in common the fact that their entire populations might almost fill the stadium for a Super Bowl. Just saying.... / sarcasm
Forced population density causes insanity. Experiments with rats subjected to overcrowding, even with all the food they could eat, showed that the rats suffered from radical increases in violence and other behavior problems. Human overcrowding causes stress and leads to mental instability. It also leads to entrenched power structures that let a few elites control the masses through application of the massive leverage of control of government infrastructure.
The bottom line is that if you force people to live at high population densities, they inevitably go nuts and become socialist ants.
No one is forcing anyone to live somewhere they don’t wish to live. So I reject that premise. However the rest of what you said seems reasonable.