Humbled, my daughter uses Kiva micro finance charity and has been lending small amounts since she was a teenager. I support Save the Children and UNICEF with very small amounts every month because it's true small amounts of money go a very long way in developing countries.
Also those charities are part of the DEC that provides relief in natural disasters and war zones. UNICEF do amazing work vaccinating children against preventable diseases. Our tiny amounts given regularly are often an undreamed of sum to a person trying to work their way out of poverty or get medical help for their children.
I believe we have power and we shouldn't give in to the idea it's hopeless. There are seven billion of us after all so in that sense 2RM we can all contribute to ridding the world of poverty but it is complex. Overpopulation, as you mentioned because of the lack of a social structure to finance people in old age.
Religion is a large problem, the Dalits, the untouchables in India are still only able to get menial work - this is God's will apparently! They don't blame people for the caste they are born into according to the Indian guide on my trip there. Really! Corrupt governments that steel all the aid that is donated or insist on bribery for even education. Many, many problems still to be overcome.