This is soooo cool, but getting a PCB made is super easy and cheap right now (chip shortages, notwithstanding). How will these types of circuits handle higher voltages and currents? Will that be simply a case of printing on the right substrate?
As a production process it has some uses, but mainly for larger, more flexible stuff. LED clothing, maybe?
Might not work if you put component pins through via holes. Plated through holes have enough hard metal to withstand that. Conductive ink, maybe not.
As usual, making your own boards is more trouble than it's worth. Board making services are cheap and all the DIY processes produce an inferior product to even low-end board services.
The US has PCB manufacturers, but they are WAY more expensive.