in places where you have a 3d printer but you don't have an active shipping line that can easily reach you. You can easily prototype things or build electronics.
I also don't see this as the final result, printers could be purpose built for this to speed up production and make size smaller
I suppose, but the 3D printer requires consumable inputs. So without active shipping that printer is going to have a very limited lifetime. There’s always a corner case, like having to 3D print on Mars or something, but thats a niche of a niche.