“Quality matters more than quantity - it makes no difference if the US population grows if that growth turns our cities into replicas of Mexico City slums.”
There’s no chance of this happening.
“with modest population growth” 2/3rds of the US current population growth is from immigration. The US needs a higher birthrate, not a lower one.
You see it happening now, in real time. Much of our population growth is either third world immigration or the offspring of third world immigrants, and they're transforming our cities into a replica of the type of societies that they came from. This isn't the sort of human capital that benefits the nation or the economy in any way.