Ugh, regarding the lack of such a twentieth century visionary, look up Le Corbusier's Plan Voisin for an idea of what such a thing might have looked like!
The problem with LeCorbusier era (IMO) is that few people may understand what he was doing, and large scale project and industries would have led to yet another clusterfuck. Also his big plan, like many utopic and euphoric ideas of this era are only good on paper or as set for SF movies (lookup where total recall was filmed)
Le Corbusier indeed built shit after he became an ideologue first, and an architect second. Before that, his family residences were quite appealing though. But those were so bourgeois, the horror.