>>514751813
What people should covet is youth.
the technical obstacles for technological-based true immortality are absolutely insane, nano-machine tech that can scour your body, repairing cells and clearing out waste, and then either remain in you or flush themselves out somehow. This would all have to work basically perfectly too.
Slicing open very young people and siphoning their blood can do this but that has its own ethical problems. Organ transplants are risky. You can regrow brain cells with stimulus (by learning new things, not with medication) but in basically every case this is a race against the clock.
Without any drugs at all, just nutrition and exercise, you can get 65 years of decent athletic ability which beats the piss out of most people that have fucked up knees and backs at 35.