I always thought conductive ink had too high a resistance to use to make PCBs. That’s not the case?

How do you attach the components to it?

Yes, conductive ink has too high resistance; at least the one that works on a basis of carbon; a "trace" can easily have kilo-Ohms, and the metal ink interface makes things worse.

I remember reading some "Sputnik" magazines from the 1970s where Russian scientists were searching for the holy grail of a good conductor resin. I didn't understand at the time why they found the (concept of the) thing so valuable; but now I've got an inkling...