I never could empathize with those arguments that go “In the transhumanist future how do you know that you’d make the cutoff for existence?” because i always assumed that (a) obviously I wouldn’t, and (b) it seems entirely sensible to me that if my non-existence were necessary to bring about the existence of a happier or better person then I shouldn’t exist. Like, even if the thought experiment was to kill me and replace me with a clone who has very slightly better eyesight than me and nothing else, I’d still say that you should kill me. At least in principle, who knows how I’d act in reality. This has always seemed obvious to me beyond question. I guess I just have atypical moral intuitions.
Say my wife and I have really good genes, such that our son would be at least equal to you in every regard, and have slightly better eyesight. Would you be alright if I killed you, if it meant that my wife and I then decided to have a child?
I would be bummed, but accepting. Actually, since I probably provide less value to the world than the average human, I’d probably have to accept being killed in exchange for the creation of a random person. And that’s ignoring the extra lifespan of someone two decades younger than me.
I feel like there’s an argument to be made in favor of preserving existing people on purely pragmatic grounds, since we don’t have to spend a couple decades raising them into competent adults. Really depends on how much of the GTH consists of augmentation at/before birth vs augmentation as an adult.
Hypothetical people don’t exist yet, and therefore only count based on their probability of existing in the future, at best.