That said, if the paper and binding quality are the same between shifts and there’s no identifying mark like unique numbering on each copy, there’s no telling how many first editions in circulation are really third shift printings. So few of the books survive the centuries that I’ve never heard of more first editions showing up than the publisher admits to printing to bibliographers.
Edit: They’re not really “worthless” but old and rare books might see one genuine first edition sold every few years to some rich person with a hobby. Many if not most of these books are bought and sold by knowledgeable collectors so if a client is going to drop thousands on a book, they're going to buy the copy that is most likely to be genuine, making any also rans effectively worthless because there’s not enough of a demand to force buyers to settle for riskier copies.
[1] because they’re unauthorized and the publisher doesn’t talk about them to the bibliographers
When I worked on an anti-counterfeiting and supply chain integrity startup, one of the kinds of counterfeits I heard was of factories that make the legitimate product secretly also make the counterfeits. (Sometimes called "third-shift counterfeits".) They'd not only reuse the design and processes, but also reuse the same tooling.
Corner-cutting the design/materials/QA is optional.
There's huge money in counterfeiting (hey, the brand hand counterfeiters their IP and brand-building and even tooling; and counterfeiters just pay materials, labor, and distribution), and some other supply chain shenanigans.
My impression was that besides hurting many businesses large and small (e.g., lost sales, price pressure, brand damage, and support/returns costs), and consumers (e.g., substandard product), it might also be concern for the relative economic power of countries (e.g., interests in one country steal profits from a major company, then that company sometimes also gets bought out by interests in that same country). (Though, bought-out companies still sometimes face supply chain fraud problems, including originating in other countries, so it's just not one single coherent national entity that's the problem.)
Had Covid not hit right after my startup's successful factory launch, and then the subsequent VC skittishness when we really needed a round (to grow our big-ticket enterprise sales/partnership and high-skilled engineering), we might've made bigger dents in the problem.