For architects of 21st century cities, most of these sustainable technologies would benefit from a cleanslate design, rather than trying to compete with builtup 20th century infrastructure.

I think Austrailia is postured to be the biggest beneficiary of all of these "leaps" in technology this century. Most of the desert area is the perfect canvas to start building indoor cities that will be the models/prototypes for the spacestations that the next generation will use to explore urban life outside of our atmosphere. Even building a cruise ship on land would be a good starting point for a 21st century city if they could support several thousand residents with enough freshwater for self-sustaining agriculture and energy to take root.

Even though we won't have saltwater in space, most of these advancements in sustainables fit the roadmap to space more than they're currently reported. Hopefully they'll break ground on new cities using these new resources sometime soon and change the narrative appropriately.