People dying is beneficial to humanity in countless ways.
People not dying is the "travesty", and preventing death is probably one of the worst things you could do to humanity.
People not dying is the "travesty", and preventing death is probably one of the worst things you could do to humanity.
What a gain it would be to have people continue their productive lives for decades or centuries longer.
The costs: we would give up having children. The replacement rate for an immortal race must be very low. The weight of old, bad ideas might be harder to shake off.
This sort of thinking seems to me a consequence of assuming that brains are somehow separate from the rest of the body, almost bordering on dualism.
They might be easier to shake off, and I suspect this to be the case, if all human brains are rejuvenated brains with 25 year-old physiology. It is not clear that "old people set in their ways" is a result of minds that have simply been around a long time, regardless of their physical condition (i.e. immortal or not), as opposed to a consequence of a physically aging, deteriorating human brain.
So we might find ourselves with the equivalent of a population composed entirely of twenty or thirty-somethings, except some of them happen to have many decades (eventually centuries and millenniums) of experience. We may well be much better off than now.