What's the point ending up dead?

After 29 years things are falling apart for Grace (Annette Bening) and Edward (Bill Nighy). Edward has found someone else. But can he just walk away, disappear into a new life? They have a son who, albeit unwillingly, is joining in as a mediator and a messenger boy between the parents. A hopelessly decent relationship drama set in a picturesque coastal town. Nothing remarkable anywhere except that it's always a pleasure watching Bill Nighy's somewhat inconspicuous and leisurely acting.