Perhaps more importantly, the societal costs of passing judgement on people to decide whether they should die probably causes more long-term pain than it prevents. Of course, most societies do this sort of thing all the time. That is, losing consciousness for ever. I just don't want to ever lose consciousness for ever, and I thus think that's the worst part of dying. The thing about losing consciousness forever is that you won't realize that you have lost consciousness and will never regain it because you will be dead.
Dead people arn't sad, dead people arn't happy.
Dead people are dead. If not, then you have nothing to fear after death. As for immortality, after a few centuries I think I would be about ready to throw in the towel. This may seem like a poor definition, but I also submit that it is the definition which you yourself use in practice. Oh, well, I guess I'm not conscious after all.