The last thing you ever want to do is extend the period of frailty and disability and make people unhealthy for a longer time period. So lifespan extension in and of itself should not be the goal of medicine, nor should it be the goal of public health, nor should it be the goal of aging science.
There is a wide, yawning black infinity. In every direction, the extension is endless; the sensation of depth is overwhelming. And the darkness is immortal. Where light exists, it is pure, blazing, fierce; but light exists almost nowhere, and the blackness itself is also pure and blazing and fierce.