I recently bought a rare book. It was a boat design book written by a famous yacht designer in the 1940s, but it's been out of print for decades and I had to pay $150 for a "fair" copy with missing dust jacket.
I have an interest in older technology and the old ways of doing things (for instance, how do you lubricate the mast of a gaff rigged boat so the gaff jaws don't jam?) I've often found myself reading very old books that have been out of print for a century.
Sometimes I read those books at libraries and I've been the only person to check them out in years (I started doing this back when they still stamped the return date on a card so you could see when it was checked out). Now most of those books have been disposed of by libraries due to yield management software and I've ended up with some of them in my personal collection, but people like me can only save a tiny sliver when most of them are being bought in mass by Sam Altman. When they're gone the knowledge in them is also gone.
We are burning the library of Alexandria and the HN consensus is "those books probably weren't saving anyway."