It’s always good to support the original publisher and encourage local libraries by reading a hard copy, so I could never endorse piracy, even for people who can’t get their hands on a physical copy. Even though it’s true that both libgen and annas-archive have ebook copies of this particular book (and can easily be found via google), I could never in good conscience direct anyone to such a site.
No idea about the movie, but I wonder if figuring out the exact quote would be a useful step in the right direction (making it easier to google, ask about, etc). The closest I’ve found so far is “The meaninglessness of suffering, not suffering itself, was the curse that lay over mankind so far”, from Nietzsche’s Genealogy of Morals.
I assume that the movie used a correct quote, so it should be possible to find the quote without knowing the movie. If the movie invented a brand new quote, then the idea of using the original quote as a stepping stone towards finding the movie won’t work.