Someday it will take just sand, energy and advanced 3D printing to create enormous building projects that cost virtually nothing.
The actual printing will be done by millions of tiny drones. some crawling, some flying, that can fuse sand together using a laser.
Buildings, homes, roads, bridges, dams...etc
Think of the construction abilities of some insects but with more intelligence and endless supplies of energy and an endless supply of worker drones.
No unions, no workers, no cost homes...it’s inevitable.
Everything is going to change.
Everything has been changing, faster and faster, for at least 500 years.
Are we coming to the singularity? Or will human limitations dampen the pace of change to a merely incredibly rapid pace?
3D printer uses concrete to construct houses at the rate of 10/day.
https://www.youtube.com/watch?v=WzmCnzA7hnE
I could see this used to cheaply create decent housing in poor areas of the world.