I don't think these are conflicting ideas. We should absolutely do what we can to fight against the aging process, which is horrible in so many ways.
But defeating aging will never mean that we've defeated death. Accidents, murder, disease, and disasters would still happen. And the 2nd law of thermodynamics would still reign supreme eventually, even over effectively "immortal" humans.
So it's important to understand and accept death, even if we continue to work towards a world where nobody has to die of old age.
Our brains aren't big enough to hold an eternity of memories, so you would forget who you were to make room for what you'll become. What's the point of immortality without continuity? That's a living death.
And forget about actually cheating death. Imagine if somehow you survived long enough to witness the heat death of the universe. Stuck on some Dyson sphere around a white dwarf for billions of years as the entire universe fades to black and all the things you used to do become impossible because there isn't enough energy to do them. And in the end you still get sucked into a black hole like everyone else, wondering if you are the last living thing in the universe.
But defeating aging will never mean that we've defeated death. Accidents, murder, disease, and disasters would still happen. And the 2nd law of thermodynamics would still reign supreme eventually, even over effectively "immortal" humans.
So it's important to understand and accept death, even if we continue to work towards a world where nobody has to die of old age.