I think we are on the edge of another revolution, like the open source software revolution that created Linux, and all the derivatives. I don't think people realize just how much open source software has pervaded their life, but it has enabled smart devices that would have been impossible at a reasonable cost if each company had to develop software from scratch or license it from the likes of Microsoft.
Open source hardware designs are the next frontier. With relatively low cost tools and a moderately powerful laptop or desktop computer, you can design and create objects yourself. You can start from nothing, start with an open-source design, or license one from someone else.
As 3D printers become more capable and can use more materials, anyone can manufacture objects. If you don't have a 3D printer, there are already services to print and even distribute objects for you. It's mostly used for jewelry now, but I think that will change.
That's for sure... literally in the billions.
Millions of servers and devices running the Web/Cloud, (65% of Web servers), use the LAMP stack (Linux/Apache/MySQL/PHP-Pearl) and most of the security device kernels (routers, etc.) are based on some form of Linux. Plus Android and most programmable devices/controllers are based on Linux.
While not open source, Apple's PC and mobile OSs are based on an open source Unix derivative (BSD from NeXT).