Earlier quoted context omitted.
>Because it's the default nobody is morally implicated in electing to avoid it. There is no smothering. The trolley problem would like a word. https://en.m.wikipedia.org/wiki/Trolley_problem
You're effectively switching the track to "Strangulate the whole planet with humans and their downstream effects!", very cool, or y'know any other disasterous permutation. We've already got population issues if that isn't compelling enough for you.
If everyone lived like the average American today, the maximum sustainable population is about 70 million humans (give or take a factor of about 2), even if they’re all mortal.
Conversely one can conceive a green tech and policy future which is compatible with having trillions of ageless humans living comfortably in what are currently deserts while the rest of the world is maintained as a nature reserve.