I think you missed the point buddy. We cannot avoid death, it's going to come eventually, whether you save them or not. And even those that are immortal end up feeling like the cycle of life is exhausting a lot of the time (it's why I'd never want to be immortal, I want to die eventually, it's the eb and flow of life). Also I've had quite a few people in my life who were being kept alive simply by medicine and trials of possible treatments that could help, it wasn't pretty seeing them still suffer.
Keeping your 20 something cousin alive is different than trying new treatments on your 80 something grandpa. I hope you understand that. And I also hope my family understands that if I'm terminally ill or have a low chance of survival, I wouldn't want to spend my last fucking days hooked up in a hospital being pumped with drugs. We all die, whether it be 5 or 95 , We. All. Die. No matter what.
I don't mean to compare grandpa to an animal, but this feels like when people try everything to keep their pets going when you know it's there time or past it... it's just suffering at a certain point... in the cycle of life we all live and die. I had a co-worker at a past job who was very death positive, in the sense that, again, we will all leave this world one way or another, some sooner, some later. It's better to go peaceful than drag it on.