Masdar has been canned, yes, but they have talked about replacing it with a new city called NEOM. It is projected to cost at least 500 billion dollars, assuming

Masdar has been canned, yes, but they have talked about replacing it with a new city called NEOM. It is projected to cost at least 500 billion dollars, assuming they stay within budget. No private actor has that kind of cash to spend. Indeed, I can only think of a few ground up examples for cities that "suceeded" and they're almost always new capital cities where the Government can literally create demand for jobs via moving the bureaucracy. Examples include Washington DC, Brasilia(Brazil) and Canberra(Australia). But these cities often do not have a lot to offer unless you work for the government. DC has a large private sector, but it's attached to Federal work. The rigidity of top-down planning removes the ability of the city to adapt to new things and it often misses the nuance of what makes a place livable.