In a world of unlimited resources violence by humans against other humans, would not be necessary. However since some of the resources humans require for survival (food) require violence to obtain, violence will also always be necessary.
I would say that technology should make life easier and people should find the necessities of life ever easier to obtain even in a world where resources are not unlimited. However, to date, technology has been used by the few to suppress the many rather than the opposite. Historically violence has been the many's answer to that oppression once it gets to a level that becomes unbearable.