As searches progress and leads peter out and it becomes more and more apparent that the person is probably not going to be found, I start hoping that they don't want to be found. That this was their decision, that subjecting their family and friends to days and weeks of waiting and not knowing, never knowing, was a necessary evil for the sake of them escaping. That they don't have to be afraid of whatever it was anymore, and that they can be free and happy.
I don't know if that's an optimistic or messed-up way of looking at it. Certainly it's not the best case scenario so much as it is a different kind of tragedy. This way one person comes out of it better, at least.