What kind of books are we talking here? Could be survivorship bias, but my experience (in Europe) is nothing like this, plenty of old books in every household and second hand shops are buying them en masse as well.
I actually happen to work in a printing house, but what I stated is something that was explained to me years ago. I'm in the software development department, but I'll ask around in the printing department and see if I can get any clarification. I do wonder if that information is local to our country, or to specific books, it was explained to me in the context of a hardcopy of Journey to the Center of the Earth falling apart. The book was likely printed locally as it is in our local language, not French.