All diseases are miserable to endure. My wife has degenerative disc just like her mother but it is manageable. I know it’s not the same as those you listed and not nearly as devastating but it can be incredibly difficult to watch someone progressively get worse.
Makes me question things (like faith, etc) when I see people with these conditions
Just awful
My uncle’s kidneys gradually failed him and he was too old for a transplant.
A friend of his was doing the eulogy and started crying saying “I’m sorry you had to suffer buddy!”
It was really sad.