A lovely poem that I'm sure can be heard wherever he has gone.
My grandfather died recently and, like you write, his quality of life had deteriorated to such a degree that it was more than his time. I think, in a funny sort of way, we were all glad that he was at last at peace.
As you go on to say, though, it is the legacy that they leave that's important: the good they did and the family that they leave behind. If we reach the end of our lives respected by a family that we have helped create, then what more can we possibly ask?