My response in another thread to a “3d printing will not replace traditional manufacturing” comment:
I disagree. I think 3D printing will replace traditional manufacturing. It will never be practical for centralized mass-manufacturing, but I think that paradigm will be replaced when we all have the means to produce custom items in our own homes (or at Amazon’s nearest warehouse, etc.).
The customization point is key. Injection molding 10,000+ of the same part may always be faster and cheaper than printing them (though we should never underestimate the power of massive parallelism: if you have 10,000 printers sitting idle vs. a few injection molding machines and mills to cut molds, the equation looks very different), but as the gap decreases, the value of generic parts will decrease in favor of custom, made-to-order ones, which is 3d printing’s big strength.