Some Saudi Arabian overlords have designed this ultra-modern, if not dystopian, mega-city to house up to 9 million people., as part of their futuristic NEOM project.
Although is has a few drawbacks (ie it is full of high-tech surveillance and will be run by misogynistic Islamists, people will be relying on bugs and lab-grown meat for their food, and non-elites will never see the outside world) the project does prove one thing: that planet earth, as created by God the Father, has plenty of room for billions upon billions of human beings.
Repeat after me:
The world is not overpopulated.
The world is not overpopulated.
The world is not overpopulated.