Below is a link to a story entitled "A Library's Past:Two grad students convinced the University of Virginia to save and store its library's card catalog, arguing that researchers and historians can use the cards," by Lilah Burke for the Inside Higher Ed blog, January 8, 2020.
"The two Ph.D. candidates, said that. . . the project is not motivated by nostalgia. They said preserving the catalog is a gift to future researchers and historians. 'We’re not arguing for the superiority of the Alderman card catalog,' Curtis said. '[The card catalog and the digital catalog are] different. They tell us different things . . .' 'This is a snapshot of the library at the end of an era of analog discovery tools,' said Unsworth. 'Our electronic catalogs don’t give us a way to reconstruct past states of the collection.' Once a book is gone from the stacks, it’s also gone from the digital catalog."
[Margaret comments:] my mother, a well-known scholar, left her professional papers to her alma mater. When the librarians came to pack up the books, they left her collection of bibliographic "cards" (actually slips of paper) behind. These slips, laid out in the way she had been trained to write them in college, represented nearly 70 years of one woman's reading and research. I almost discarded them, but then I realized that they represent the end of an era of paper technology that stretches from the early modern period through the end of the twentieth century. Some day, if I can find space for them, perhaps scholars will be interested in this evidence of the material culture of learning in the twentieth century.
Although she specialized in print culture, I'm not sure my mother thought about how her own files might fit into that long story, but I am happy to hear about these graduate students.
See "How the Index Card Catalogued the World," https://www.theatlantic.com/technology/archive/2017/12/how-the-index-card-catalogued-the-world/547271/