I have two replies when as a criminologist studying firearms issues I am asked would the world not benefit if there were no guns? First, 1200 years ago there were no guns. Yet, for excellent reasons, that period in Europe has been called the Dark Ages. Firearms are the only weaponry by which the weak can resist the strong. Their absence was characterized by oppression and massacre not peace.
Don Kates, quoted by David Hardy at Arms and the Law.
Kates's other reply is worth reading too.