curiously enough this phenomenon is an instance of Goodhart's Law, in that for them, books have become the optimization target themselves, rather than a proxy for being well-read; as such, it becomes more important to acquiring and showing off books than the ideas they contain.
to be super clear, none of this is inherently bad; signaling ones proficiency at the game of books is highly instrumental to acquiring status within certain nerd-flavored circles. it's just orthogonal to the game of ideas, which some of these people claim to be playing.