The movie was so much more profound than the book.
The movie explored the question: What would you do if you met your maker?
Roy told his maker, "I want more life, effer."
To which his maker said, we made you as best as you could possibly be.
Of course, the creature was unsatisfied with what all his creator gave to him, so the creature proceeds to kiss his maker and kill him.
It was a futile act, because the creature itself dies eventually.
The moral of the film: You can be unhappy enough with yourself and kill the one who made you (atheism), but it won't change a thing.
“The movie was so much more profound than the book.”
Often the case with PDK stories. They’re good/deep as written, but clearly a product of their era (a time I’m respectfully losing respect for).
Book: Deckard is human, coming to grips with his preference for real over indistinguishable artificial copies.
Movie: Deckard is ... we’re not sure. He’s coming to grips with how human replicants are ... while the replicants he targets come to grip with how, ultimately, they’re not.
The book/movie difference really does come down to a “left vs right turn”, as Deckard returns to the police station about 1/3rd thru the story.
“...and that made all the difference.”
I rate the book as much more profound than the movie. The book is a meditation on how humans destroy their own humanity. In the book there’s no question that Deckard is human, but his humanity has been eaten away by his job, wife, and life on a dying world; so the replicants have a much higher level of humanity than him, even though they aren’t human. A big part of the book is him rediscovering his own humanity, but in the end it’s a lie he’s telling himself, his humanity is destroyed and he can’t get it back.