You want to know why there is war and famine when others have food, why there is poverty when others have riches beyond imagining. In the grand scheme of evolution, most humans are quite young. You can see this in the choices made. Altruism is a sign of maturity. Do not think that age in this lifetime has anything to do with it. That is a local phenomenon. Think in terms of evolution of the species and know that each choice you make either propels you forward or holds you back on a personal and unified level. May this understanding help you to find peace as you see child-like actions in humanity. Be cautious as you might judge, for you would not judge a child for doing what a child does. Instead, guide others and model mature action.
You are so very loved.