> any important book has been duplicated by thousands, tens of thousands or even million of units.

Books in the former USSR display their print runs on the last page. "Important book" is a vague and arbitrary term, but rhere are works in whole fields (e.g. history, archaeology, linguistics, ethography) that any scholar would consider key references, and as few as 100 copies were printed.

The shadow libraries have made a lot available to the whole world. It would suck if private corporations scan and shred remaining copies of these before the shadow libraries can get a scan.