> Somewhere, you need aluminum smelters, steel mills, and copper mines.

Why? We already have plenty of materials that can, are close, or have potential pathways for functional substitutes depending on the application? We are already pretty reliably able to print metal with machines no bigger than a fridge.

What happens when a curable resin or impregnated plastic can sufficiently replace steel/aluminum/copper for functions? Why would a steel foundry be needed for the desktop then? There are more theoretical materials that haven’t been discovered than there are atoms in the universe or something crazy like that, so it isn’t beyond the realm of possibility or even likelihood. Especially if AI helps accelerate that discovery, as it seems to be doing already according to a recent Faraday talk in a Royal Institution video — "How AI is Reinventing the Battery".

It also used to be that you needed a large machine to make a plastic part…now I print some in 20 minutes with something that sits on my desk. If one thing is true, it’s that materials and technology constantly change and (generally) improve.