After being clickbaited and ragebaited, media consumers feel deeply anxious and angry. But, explaining that they are angry over a boring situation feels silly, not righteous. So, they give summaries, impressions, sometimes extrapolation of the bait they have been consuming. That feels righteous.
This observation applies to a wide variety of topics trending in the various media every day. Distinguishing injustice from ragebait unfortunately requires non-trivial effort from the reader.
Why are you assuming that each book gets scanned exactly one time and then never again? And why are you assuming that out-of-print books remain easily accessible so long as not every copy has been destroyed?
>Your local library throws out books every year and nobody thought twice about it.
When they're damaged beyond hope of repair from decades of wear. As for books that haven't fallen apart from being used as intended and merely are no longer desired, my local library generally sells them off at bargain prices. Of course I can't speak to your local library.
I even read on a web site of a librarian that their library had stopped accepting donations because "patrons should know how to throw away their own trash".
What happens when the books don't sell?
Many books aren't lent and not bought and most libraries have limited space to store such books, thus they go where old paper goes.
Of course some rarely lent books are important and for the one person asking for it in ten years really valuable, but many still have to go.
I know it comes at a shock but truly most books are absolutely worthless.