Interesting idea but millimeter-scale logic doesn't really have much practical use in this day and age :) but it's s nice proof of concept.

Ah - but it's not just mm scale - it's 3d mm scale - sure it still needs to be smaller but if you can print into volumes rather than just on 2d planes things get interesting

Yeah, but a GPU would still be the scale of the pentagon :P

Even placing traces inside a print and then slotting in IC boards would be useful.

Even at mm scale it changes the types of prints that can be done.