> Everyone becomes a liability at some point. By that logic we should just go full Logan’s run and kill people as soon as they stop being productive.
That's ridiculous. People can be unproductive, but not a liability.
> But I don’t want this attitude of “you should kill yourself so you don’t burden your family” to become the norm either.
I can see that, but you haven't explained why. Personally, I don't want to burden myself, my family and those I care about, that's important to me. There must be something more important to you that justifies burdening loved ones with a hard painful death of a loved one. Help me understand: what's that thing for you, if not ego/fear?
> What if your partner’s grandad heard you calling him a rude obnoxious liability and felt pressured into killing himself?
The alternative is he's unnaturally kept alive in a perpetual state of suffering for him and the people around him. If he hadn't suffered mental decline, I know he'd never consciously choose that, another reason why I'd like to make sure I'm gone before serious decline kicks in.
> But many people die suddenly with no serious mental decline at all. That can happen at 95 or 100 the same as it happens earlier.
That doesn't change anything. I agree with Kahnemans point that becoming a burden is too late. If I accept that, without being able to predict the future, it then becomes a game of risk. Kahnamen decided the risk of him becoming a burden was greater than the risk of him continuing to live what he would consider a productive (edit: "valuable" is probably a better word here) life.