You know, if you gather all the people in the world, and give them 1,000 sq. feet of living space, they would only fill up AZ, TX, CA, NM, NV, WA and OG.
The rest of the planet would be empty, and you could grow food and raise animals for food.
All depends on what the people of the world want.
Most want greed, corruption and control of others, not what is for the benefit of mankind.
Such is the nature of the human condition.
The answer is get along with each other and work for the benefit of each other.
Capitalism works best at this, socialism works the worst.