I do not understand the question, trying to speculate I can say that the "downtown" model was needed in the past, where anything was on paper so it's useful to have a specific place where all paper works are done, while others for specific activities like commerce, factories producing various goods and so on. A "zoning" mandated by the need of physical proximity. As an example you file your revenues declaration than you go to the bank nearby and pay what's due, since you are there you also go to your carrier to ask for another contract etc etc etc, similarly before supermarkets you go to a specific place where anyone commercializing food go so in the same area you can buy meet, fruits, bread, ...
You can see this model as the "universal city factory".
This model need density, not too much but enough and it's not only not needed anymore, but it's now incompatible with current tech and climate change. Since the '80s logistic became cheap and quick enough that delocalizing became a better option then being nearby your customers, with modern TLCs/IT we do not need the office anymore because we do not need to work with paper physically walking around. We need websites/APIs as "the office where you need to go to file tax, make a payment etc", a desktop as a tool to act instead of walking around. Modern logistic also demand space: delivery anything in a dense city is a nightmare delivery in a sparse area, not too low dense but still sparse, it's a pleasure, there is room to park everywhere, no issues reaching the nth floor with potentially heavy and big package and so on. Oh, yes you need to travel a bit more, but hey, there is plenty of space for p.v. and your delivery van fleet might have quick replace batteries like Renault QuickDrop at yours warehouses. Similarly those who not WFH still have parking places where they work in a fixed location to plug their EV and recharge from local p.v. being not anymore artificially spread for the sake of car makers like USA suburbs but being intermixed like EU Rivieras you still do not made too much distance to have recharging issues. Having a bit of space around and small buildings allow for cheap constructions and evolution. This is the new "right density" for the economy of scale.
Only there are some looser: in this model we all own, so no market for Uber, we eat in fixed locations with plenty of space, not while commuting so, no market for Just Eat, room at home for anything so no various services like public washing machines and so on. The financial capitalism loose dramatically while a new spread, quickly evolving, in a constant change without the need for much revolutions, of SMEs etc flourish. Not everything can be done at this scale, like steel production but hey, even Apple have planted a small foundry hidden nearby some homes. We definitively can work in most cases at small scale. Unfortunately the big losers are also much powerful and disagree.
> You can see this model as the "universal city factory".
> This model need density, not too much but enough and it's not only not needed anymore, but it's now incompatible with current tech and climate change.
Interesting, that's backwards for me. It's true that technology means we no longer have to shuffle pieces of paper around, but that doesn't change the fact that some people like being around other people. As far as climate change, imo a few dense core cities are better than endless suburban sprawl because by taking up less per person, there's more left over for nature. If it's dense enough you don't need a car which is better for the environment because you're walking everywhere.
Apple gets away with a tiny foundry in Cupertino because they have Foxconn to run great big factories in China. That's not a globally workable model.
Liking does not means is cheap or sustainable though.
> few dense core cities are better than endless suburban sprawl because by taking up less per person, there's more left over for nature.
Actually it's the opposite, first because you do not need less per person, you do need more in natural resources:
- big buildings demand much more infra around and themselves consume much more raw materials to be built, beware that OLD buildings are another beast respect current one with seismic and fire safety, energetic performances, ventilation and so on. In the past a small 4-5-storey building (let's say 20 apartments) was on-par or even a bit cheaper than 20 correspondent homes because homes tend to be bigger and have 20 roofs. But such ancient buildings does not care about how much energy they need to heat, they have no cooling, no seismic designs, ... they are just "CA boxes" stacked around with small additions (clean and dark water, electricity, windows etc). Things have changed, elevators, stairs, also have their slice;
- supporting infra is much more impacting as density, few dense are is like sit on few staple, it hurt, MUCH, you create heavy masses (subsidence), divert much water altering water cycle for a very larger area, produce much concentrated pollution, absorb much heat (a big slice of thermal mass exposed to the Sun) and so on, again modern cities are not old ones still made of small buildings where peoples tend to work at ground floor living "just upstairs", there are still no factories in cities anymore, because nowadays change is quick enough and scale vary enough we need room to change and a dense city is too dense for that, so you still need to go back and forth the city and moving all goods etc;
- finally the most important: cities can't evolve. Today "A-class" homes are tomorrow G-class, today needed infra are tomorrow relic and missing new needed infra, just see how hard is in dense EU cities parcel delivery. We have had parcels before, they were just rare and letters just common, now it's the opposite so they can't got delivery on feet by the postman nor they enter the small set of post box in the hall and it's a new logistic nightmare, such a small change such a big issue. To change a city you need to rebuilt it and that's dramatically expensive.
Also, nowadays in spread area (beware, spread A BIT, not large ranches around the Steppe) you do need to travel MUCH LESS than before, first all works doable from home should and can be WFH, witch just erase commuting for a big slice of population, having longer trips to buy food means you stock more at home and you have room to stock, so for instance instead of buy small packaged stuff where the package is single use and prominent respect of what's packaged you buy large stuff with much less disposable package. Being able to do much more via web means again much less trips. In the end you travel of course, but much less than before, and you can travel electric on scale, because most people can recharge at home or at work (where the work is in a fixed place, from local p.v.). You probably thing about USA style suburbs where there are ONLY homes for a very big area and somewhere else ONLY shops etc, such design it's not the spread design, it's the Ford design to sell more cars. The kind of density I advocate is the EU Riviera model, where homes and shops are intermixed, so you still have few shops in 1 km, a school nearby and so on. Where you can live in a 30km radius instead of 15' walk ignoring the immense infra and supply chain needed to serve you in the 15' setup.
The only who benefit from modern dense cities are those of the financial capitalism that need such "big scale" to rule, at a less dense scale they fail. Maybe local foundries are untenable but that's not true for much more, in the end we can have few cities to serve some productions composed only of workers for a certain period of time, of course workers have family, children but it's still a temporary location, they'll go out when retiring or changing job and in that case such cities became much smaller. The New Urban Agenda essentially agree we can't build large dense cities, Neom, Arkadag, are good examples of such failure as original Fordlandia, but they still hope to build small cities of essentially slaves, who depend by third party services, owning nothing, to live, and even if that's might be possible it's not good for nature nor for us. Now take a look at "urban" air mobility push https://www.easa.europa.eu/sites/default/files/dfu/uam-full-... did you think it could be "urban"? I think it PERFECTLY much a spread living, matching actually the old model of the gentleman who run by car seeing slaves working by feet around, the advertise like https://appliedevtolconcepts.com/ who perfectly mach '30s car advertisement.
