You haven't "lived" (period) until you're dead, and it's settled.
You might have e.g. "lived in London" (if you don't know, so it's a settled thing and a specific period of your life). Or "I've lived in poverty", etc.
But "I've lived", period, without such a qualifier is not that common or useful when one is still alive.
If you truly want to argue that the verb tense chosen means "Everyone who ever lived [and then died] has died," then the statement becomes a tautology: "Everyone who has died has died."
All true equivalency statements are tautologies -- since both sides "resolve" to the same thing. That doesn't mean they are useless.
In this case, though, it's not "Everyone who has died has died", but "To have lived means you're dead".
The same way that "to be a corpse means that you've died". That's not a tautology (it's not "to be a corpse means you're a corpse"), just informs us of a prerequisite for the other thing to happen.
