That is what I took from the Book and Film,after a great deal of thought,lol.
The difference between Human and Replicant in the end was the programmed short life-span.Genetics.
Even today there are people with a life-span of only 30-35 years,due to genetics.
And at the risk of offending,I have also seen the relevance of the Replicants being an echo of escaped slaves,back when Africans/Blacks were classed as being souless,and therefore could be classed as animals/beasts of burden.
.P.k.D. please remember,also wrote the short and gut-wrenching story,"Pre-Persons".A story set not too far in the future where the Wife in marriage was legally allowed to abort/kill her child up to the age of five.
That's five Years out of the womb,not five months pregnant.
A very well known female author was quoted soon after that she would like to smack him in the mouth.