Why do we have Wars? Why cant we all live together with peace and love?

Humans have regularly fought wars since as long as we know! It may be the case that many of the major changes of civilizations have occurred due to wars, is it really necessary for wars to exist in the story of humans? Why cant we just help each other and live in friendly conditions? Cant developments and progress happen faster in the absence of wars? Don’t we have a better alternative to solve problems?