I want to clarify that they actually did build a transistor-like device, and not just hypothesize about it. I missed section 3.2 when I initially skimmed the paper, which demonstrates and shows the results of a working “transistor”.
Unfortunately I can’t edit my original post, so apologies for causing any confusion.
It’s cool for tinkering, and I think there are lots of potential use-cases for conductive filaments and printing in electronics, but I don’t think transistors are necessary. Silicon crystal development is really already a sort of “additive manufacturing”, and I’m not sure what purpose would be served by re-inventing a method that would be starting so far behind in terms of scale, precision, and cost in relation to traditional semiconductor production (anyway, I assume this idea is broadly for learning/experimentation/the lols, rather than some earnest aspiration for using metal-bearing printer filaments to produce active components).
Unfortunately I can’t edit my original post, so apologies for causing any confusion.