Clinical immortality? Seriously, there's people opposed to clinical immortality? "No thanks, I'll take slow death"? You have two choices, pick one:
A) Hug your great-great-great-granddaughter (titanium-laced bones, skin strong as spider silk) and tell her that you've chosen to leave this world at the age of 250 as your brain has finally filled up and you figure it's better to have a new person than to start removing memories or relying on computers. She laughs and tells you about the new neuron upgrade.
B) Start forgetting things, slowly but surely, your granddaughter with tears in her eyes as she reluctantly signs you over to a nursing home. You don't know who these people are, you can't remember their names or even what you had for breakfast this morning (some form of mush, most certainly), the uncontrolled prions of Alzheimer's ravaging your thoughts. There's a four-digit code to get out of the building, and it's the current year. What year is it, again? You have no idea. 2010? Is Barack still president? By the time your lungs finally stop moving air and your DNR kicks in, you don't even remember your name.
Yes, this
is fantasy. You're representing it in the most romantic and fantastical terms possible without explicitly saying "you'll never die if you clap your hands and believe".
Death is always inevitable. Nothing lasts forever, including you, no matter what snazzy computers there are. Whether you last another ten years, eighty years, thousand years, or eight-hundred-thousand years, you're going to die, whether it's because of old age, a firmware error in your Magic Transhumanism Robot Head, getting hit by a train, some other random problem, the Sun exploding, or the heat death of the freaking universe at large, you cannot count on scientific progress ever approaching a "deathless society". We'd have to break far too many of the known laws of physics, and at that point, you're going past scientific speculation and more into the realm of abject fantasy. Sure, maybe someday post-human scientists living in computers inside tubes will figure out how to reverse entropy, but if you're going to violate the laws of physics, you might as well say "maybe they'll found out how to make me live forever in a stable timeloop like in that cartoon I saw that one time".
Maybe we'll figure out how to achieve clinical immortality in the sense that lobsters have it. Maybe scientists will figure out how to go further than that and prevent disease and aging in general, or even industrial accidents and the like. But no matter what happens,
people will still die. Death is not a question you can answer by simply avoiding it, or pretending we'll ever make it cease happening. You do not answer a question by pretending the question will be eliminated, especially not when it's something that can't be.
You're romanticizing transhumanism because you're pissed off about the human condition. This is natural. It's also hideously indicative of the same parts of human nature you probably hate, like the frequency with which we make decisions and adopt beliefs simply because they make us feel better emotionally. You don't like human nature, and you don't like death, so you're speculating that maybe someday we can be rid of those parts you don't like, and that we can live forever as some sort of hypothetical post-human society composed of individuals (or collectives!) that better fit your ideals.
I'm not saying you don't make any good points, but you're no better than those aspects of humanity you disparage, are no more qualified than anyone else (and if there's a decent metric for even judging competence at this, there are probably people a whole lot
more qualified), and are romanticizing the hell out of this concept for your own personal comfort. It really sounds like something you don't even want to question.