You see this?
1 trillion dollar megaproject. It's a self-contained city that will be as high as a skyscraper and extend out in a straight line for over 100 kilometers.
I admit it simplifies infrastructure. One line of track under each side lets them move passengers and freight. Each section will allow residents to walk to work or to stores or entertainment venues. No need for cars. Electricity and water infrastructure is simplified.
The design is efficient.
However I think the size is so gargantuan that they have vastly underestimated the cost and construction time. It's going to cost more than 1 trillion dollars and it's going to take at least 100 years to build, if not more.
If it's steel frame and glass architecture it's going to strain Earth's resources. They're going to need all the steel. All of it. And all the glass too.
I think it would work well if they could actually build it. But I don't think they'll be able to build it.