The magic of concentrations of people is that the advantages scale faster than population growth because of the network effect.
Which, separately, is why cities are awesome and population density is a good thing for the planet and most people, even if it upsets some people that they can't have a big yard.
Smaller cities like Boulder, Fort Collins, etc offer a decent amount of variety while eliminating the majority of the problems with the large cities.
Career is about the only thing a big city can be critical for and you have to be in the right city for your field.
I wrote this to contrast any size city with places like the endless suburbs or rural areas, not to create a hierarchy of "biggest is best".
Problems do also scale with size, so it's not like the massive benefits of cities are tradeoff-free. For as great as San Francisco is purported to be, they have a huge homeless problem that they seem to do relatively little about.
However, your argument is not valid: Large size doesn't imply high cost. Neither Shanghai (most populous city) nor Manila (most dense city) have higher costs of living than SF.
This comment doesn't take away from your point - but isn't densest either Dhaka or Mumbai?
https://en.m.wikipedia.org/wiki/List_of_cities_by_population...
That makes sense. Thank you for the reference.
You know - it's funny. Paris rates above Hong Kong (which does not even appear in the table), and Paris never felt (to me) as dense as HK. Even Manila never felt (to me, subjectively) as dense as HK.