Besides, if I wanted to counterfeit I would [naïvely] get one of those tight tolerance watchmaker CNCs and have printing stamps made out of aluminum or something. Printing to paper in the usual home-office way seems to me an asinine method which is easily detected by most people who handle bills regularly.

The point of these technologies is to stop the low hanging fruit and trace the source of ransom notes, leaked documents, and the like.

For counterfeiting, a technical person's first thought is: "how does the Bureau of Engraving and Printing actually do it?" and then they do that - and you nailed it: offset printing.

Laser printers and inkjets can't even remotely compare.

That's a lot more work, skill and initial investment required than just trying to slap a dollar bill on a copier. Which means a lot fewer people will try, especially since the people with these skills can usually easily make enough, and possibly more, money through legitimate means.

There were people who did counterfeiting "right", down to getting real printing presses, suitable paper etc. https://www.businessinsider.com/frank-bourassa-on-how-he-cou... (it's strongly implied that he got away with 6 weeks in prison and likely got to keep a decent amount of the profit).

Ya gotta do what the cartels do: bleach out singles and print $100 on it so it feels right