> There was certainly a contingent who believed that 3d printing was going to replace all other forms of manufacturing. It was even going to make custom food for us on order.

Yes. Met those guys in my TechShop days. They also insisted that 3D printers should be made with 3D printers, which resulted in a generation of flimsy, inaccurate machines.

The current generation of serious 3D printers is very impressive. Take a look at Space-X's Raptor engine. A rocket engine is mostly one piece of complicated metal with a lot of internal voids. That's something 3D printers are good at. Once 3D printing was able to print stainless steel and titanium, it could be used for hard jobs like that. PLA just isn't much of a structural material, even with 100% fill.

Serious 3D printers are found in machine shops, not homes and libraries.