Why even make a decleration of human right?

So I'm guessing that we can all agree that the world will never be perfect. So much conflict here and there, and evil never stops. What is good without evil, and what is evil without good? So why even make a decleration of human rights? It would be impossible to enforce since the decleration states that human rights are universal. Even now there are still slaves and battles going on, terrorism, totalitarionism, dictatorships, segregation, ect. So why even bother?