I think we're talking about different kinds of ply. One one hand there's construction grade marine plywood and on the other there's high quality laminate from exotic woods. The two are pretty different in most respects. I can pick up a bass and tell just by playing it acoustically whether it has a cheap ply body because I lived with two of those basses for five years.
I came very close to buying a switch guitar once. The original Parker Fly was laminated as was the neck on a Kubicki bass. I think there are limitations with plastic 3d printed guitars due to the structural qualities of the thermoplastic used but with metallic sintering there might be some opportunities. It's quite expensive to invest at the moment though.