3D printing is not a scientific revolution. The science has been available for decades. 3D printing is a manufacturing revolution. Instead of subtractive manufacturing we now have additive manufacturing where you can do things that previously could not be manufactured in one process step.
One way to create a marketing campaign is to compare speed between 3D printers and injection molding.
However there are many variables to actually profit from additive manufacturing.
Build volume is a key variable for some market segments.
Quality in the finally product now depends on slower speeds, layer height and other variables when using FFF or FDM.
The big corporations are going to be using lasers and technology that "Makers" can not afford and don't have room for at home.
Additive manufacturing will use different technologies in the appropriate market segment to increase the speed, improve quality and drive down the costs.

The market for 3D printers will have many different market segments depending on the results required.

Additive manufacturing is growing exponentially in different market segments at the same time. Many small businesses now have a 3D printer. Much of this is invisible to us except for a few news stories pre-selected for entertainment value.