And not just physically. The emotional, even spiritual, agony is often worse. Today our medical hardware is so sophisticated that the period of suffering can be extended beyond the limit of human endurance. There's no point. In fact, it's downright inhumane.
People have a right to die with dignity.
Nobody wants to end up plugged into machines and wired to tubes. The very thought insults the whole concept of what it means to be human. People are entitled to dignity, in life and in death. Just as we respect people's right to live with dignity, so we must respect their right to die with dignity. In the case of the terminally ill, that means people have the right to refuse life-sustaining treatment when it's apparent to them that all the treatment is doing is destroying their dignity, and reducing them to some subhuman level of humanity.