It's not a matter of economic prosperity, it's a matter of equitable distribution. If we all had a more or less equal chance to survive and thrive in life, we wouldn't be so inclined to attack others for what they have, that we don't. But unfortunately, the human inclination is to respond to good fortune and abundance with greed: to hoard anything we have or get that we don't need, or deserve; thereby denying any opportunity of gaining it, to everyone else. The wealth and opportunities pile up in the hands of those who are most unwilling to share them, forcing everyone else to go without until they are are driven to try and take it by force. At which point they also want vengeance as well as their share of the wealth, and that begins a whole 'tit-for-tat' cycle of violence that can go on the many generations.
All of this could be eliminated if we would simply design and implement a socio-economic system that equitably shared wealth and opportunity. But so far, we just can't seem to do it. Fear and greed drives us to hoard whatever we have, and to resentment those that are doing the hoarding, and eventually to shortages that propel us to violence. Over and over and over, again.
But now there are so many of us living on this planet that our greed and stupidity are threatening to destroy not just us, but the planet, itself.