What's the end goal of this remark? What's the end goal of learning to farm and produce food even when the weather and pest gods don't bless you this year? What's the end goal of learning to heat your hut instead of dying every winter?
Because it will utterly end all societal development.
Imagine if fucking Ghengis Khan never had to die.
Or Henry Kissinger.
Or Carnegie
Our system is struggling under the immense weight of old leaders and the best they can do is pump themselves full of weird drug cocktails to have some semblance of being alive. Imagine removing the last roadblock to eternal life for the richest human alive.
People would develop in different ways if they could live to be 1000. It would hardly end societal development. I imagine education would be a bigger deal, since you'd be in less of a hurry to get on with life at 18. Families would be larger as more generations were included, which could create more nurturing and supportive environments for at-risk children. You'd also have fewer trust fund babies living off of the inheritance from a dead relative. And the sheer amount of brainpower and life experience we lose every time a 90 year old dies is depressing; science, technology, and literature could all benefit from people living longer.
What is the purpose of this question? "Yeah sure, we're fixing people's problems that cause pain, suffering, loss of productivity, death, etc, but what is the ultimate goal?"