In technical terms Indonesia is trying to rebuild Jakarta deep in mountains since they can't evolve their drowning and unlivable capital, Turkmenistan have created/actually create Arkadag a novel Fordlandia equally distopic and a similar failure, the Saudis have started Neom then they reduce their goals from original 170km (105 miles) to 2.4km just trying to keep the prestige. The fact you technically can does not means it's not a nightmare, with unbearably high costs for a very poor return.

The main point here is why building/living in a city. The answer in present modern time is: just to be slave, all other good reasons are not there anymore. In the past cities was needed for many reasons, the second last ones was for the economy of scale, a big number of SME and large enterprises nearby so ideas who travel, ferocious market that push innovation and keeps the cost low, workers and customer in a short range. This collapse in the '80s when logistic evolution reach a point that cost less build things around the world and move them instead of doing anything nearby. The last one was the office. Things was done on paper, and you can't have nth copy of the same archive at home nor have customers at homes of every workers, updating their addresses as they move. Yes, we have had some forms of TLC and IT, but nothing really widespread and even if since the '80s we formally have enough to be spread that's not practically doable till very recently where videoconferencing, and screen sharing from The Mother of All the Demos became something most people use here and there or even daily. Now the city have no more purposes except one: the finance capitalism. Uber can't exists in a spread population, anyone have cars or something else to move and there is no parking issue. Just Eat the same, if you live at home, working from remote or in a spread area you have no reasons to look for ready made food in most cases and when you want there are only 2/3 options nearby, no need for an app to choose. No usable distance for ready-made food delivery robots and so on. No need for cloud+mobile. The "home world" is a distributed ownership society, there is no room for giants except for some industries NOT IT, nor finance between them.

Here the reason you here so much propaganda about green (dollar, not spring grass, or stereotypical toxic waste leaking from rusty stems) cities, "in 2030 you'll own nothing" and so on. Finance need the ability to control people, the economy is the lace, the zero public ownership the key to use that lace because in the 2030 WEF model the 99% are not entrepreneurs but employees and the 100% of their income will be consumed to live in services, being bound to obey since without a regular income they can't survive for more than a very little timeframe, of course no heritage, that's why inheritance taxes are so high where the WEF have more power and the narrative state that's good, because they know the "social lift" demand more generations to lift someone from poverty to richness and if you erase that the poor will remain in poverty without even knowing that because they have a handful of services like drugs to consume like junkies. For similar reasons educations reforms have built more and more specialized people, unable to see the big picture, unable to march on their own feet.

I fail to see any other reason for cities. Oh, yes, a teenager need to be together many others of his/her age, but that's easy done with campus model from high school, like Sweden (try to) do, giving students a flat in dedicated areas like small cities in the end. Similarly we can't make steel at small scale, so workers of this sector, during their working life have to live nearby a large factory so in a kind of city and since they do work there for a significant period of time they will have families there, but still as a temporary settlements. In the modern world doing more than that is untenable like original Noam design, the entire India is needed to built the Modi's 100-smart cities, while living spread we can be much more, so producing and innovating much more.