The main factors that contribute to a decreased quality of life are the same ones that eventually kill us. Namely, heart disease, cancer, diabetes, and the general cognitive/motor decline that comes with aging. If we could effectively halt senescence, we'd be able to expend fewer resources on care for the elderly.
I'd say that burden isn't as much for the whole society, as for the family of each person and for that person. And it should be the decision of person (and maybe its family, but there's controversy there) if that person wants to live longer causing this burden.
I don't think state or science should decide on such things. And it's better to at least have a choice.
No. That is hyperbole in the extreme. I'm not talking about killing people once they reach 100. Take it down a notch.
The article discusses gene therapy to change animal biology to artificially extend lifespan before the complications of age present themselves, ie. in the middle of the animals life, not after the animal has aged. I'm questioning the societal benefits of this to humans.