Imagine a world where you broke a leg off your chair, no problem 3D print it. They forgot you give you an integral piece in your new desk setup, no problem 3D print it. You need a part for your car that broke, no problem 3D print it. I am imagining a world where it is just as easy to 3D print anything as it is to 2D print anything.
I am imagining a world where you can recycle and grind down your old 3D printed products to make new ones. A closed-loop system that never has to dispose of materials. There will be a 3D printer in every home in America and it will be utilized all the time. You need a case for your phone? 3D print it. You need a new salad bowl? 3D print it.
The obstacle here is price, versatility, and ease of use. This printer has to be affordable, able to print a magnitude of different things and print them fast, and it has to be extremely easy to use. These three terms will get a 3D printer in every home in America. It will revolutionize how commerce takes place. Instead of buying products online or in a store you will simply buy the print file and print it yourself. You will never have to leave your house.
Now, this might be far into the future but constant innovation and early adoption will allow this idea to become a reality in the coming decades.