Business opportunity here to replace this?
Start with some HN or Reddit style forum discussion code. Some income could come from affiliate links to indie booksellers. (Is there even infra for such a thing right now? Need to build that too?)
Edit, answering myself, this guy has some thoughts: https://tomcritchlow.com/2020/04/15/library-json/
Edit, as for the index corpus, the USLC does okay: https://catalog.loc.gov/vwebv/search?searchArg=0312937385&se...