I hope so, it would shorten posts like this one.
Same as now; basically that happens whenever there is a lethal scarcity of resources and somebody has to die or everyone will.
But - ancient societies often didn’t have the resources or knowledge needed to keep the infirm alive, and sickness was far more dangerous than it is now, so you’re still touching on a real issue. I just want to make the point that it’s not a moral superiority we enjoy, it’s a (possibly temporary) resource superiority.
I’m older than you and I will make that N=2.
Same as now, if you made it past 30 or so. But the average lifespan is way different because of the much higher mortality associated with childbirth - infants and mothers were at a dramatically higher risk and dragged the average down.