The killer app could be 'parametric' thereby needing digital-to-physical manufacturing such as 3D printing. For standard static items made in plastic, there are

The killer app could be 'parametric' thereby needing digital-to-physical manufacturing such as 3D printing. For standard static items made in plastic, there are no signs what so ever that injection moulding will become redundant any time soon. In the case of normal printing, the desktop printer didn't kill the rotary printing press, (althought the internet digital press may). Desktop printers and rotary printing presses exist for different use cases. Printing notes to red mark or travel tickets vs. a glossy magazine/newspaer. The relationship is akin to 3D printing plastic / injection moulded plastic and will likely have different use cases.