> certain weird technology and library subcultures, but few people outside of them would even notice it if disappeared

It's pretty much indispensible to anybody who's a researcher.

It's very frequent that you're tracking down citations to webpages that don't exist anymore, and the IA is the only way to find sources.

Not to mention that it's also often the only way to quickly get access to non-bestseller books that are more than a couple of decades old, which is also commonly needed for research purposes. Many of these books are only otherwise available in the country's largest research libraries. (Google has copies too, but nobody can view them.)

It's not weird or a subculture unless you think those labels apply to researchers. And there are a lot of researchers out there, across academics, non-fiction authors, and journalists.