Assuming that you can avoid the problems of "old" cities by simply starting out with the right "new" city is like assuming that you can avoid scaling a web appl

Assuming that you can avoid the problems of "old" cities by simply starting out with the right "new" city is like assuming that you can avoid scaling a web application by starting from the very beginning building micro-services. The "new" city that plans for being big will never attract enough people to grow much like businesses that start with micro-services will never be agile enough to find market fit and grow to actually need micro-services. Money and effort would be better spent looking at and solving the plight of cities that have seen hockey-stick growth. Then you could take those lessons and watch for the next city at the start of a population boom and ensure that it grows in the "right" way.