We also thought 3D printing would print us a car, but alas.

FWIW - 3d printing has come a far way, and I personally have a 3D printer. But the idea that it was going to completely disrupt manufacturing is simply not true. There are known limitations (how the heck are you going to get a wood polymer squeezed through a metal tip?) and those limitations are physics, not technical ones.

Agreed on 3D printing but that is a technology that would have failed my screening as proposed.

They haven't continued to see massive adoption and improvement despite the flaws people point out.

They had initial success at printing basic plastic pieces but have failed to print in other materials like metal as you correctly point out, so these wouldn't pass my screening as they currently sit.

The fact that I needed a bag clip and just have to search on an app on my phone for one and hit print, mostly trouble-free, says that it's here. Sure, spending $1500 to save $3 isn't economically optimal, but 3d printing has disrupted things. Just look at the SpaceX rocket engines.