I think everything you said is reasonable and valid, and even if there's a thing or two I disagree with, I wasn't trying to invalidate your opinion. I was just trying to frame the discussion a bit.

1: Should the law allow terminally ill, but mentally sound, people to take their lives? (Doctor assisted suicide.)

2: Should the law allow us to end someone else's life, someone with an unsound mind, if the person doesn't express any wish to die, but is suffering from a terminal mental illness like dementia, with no cure, because the person's spouse or children think it would be for the best if they die today instead of letting the illness play out until the end?

#1 seems to have a fair amount of support from lots of people.

#2 is something most of us have agreed is a reasonable thing to do with our pets. I think it's going to be very, very difficult to get the average citizen and/or many lawmakers on board with allowing it for humans.

In any event, I do agree with you that dementia is a messy and difficult problem, and unless a cure is found, we're going to get more and more of it, as people start to live for more years than they used to in the past. It's both costly and torturous to go through.