In terms of income, the panelists on this site by and large belong to humanity's top ventile (5%) -- where the average income is 9 times the global average. This is roughly 300 times more than what is available to people in the bottom quarter, where average income is about 1/32 of the global average. (The difference is still about 100:1 if one adjusts for purchasing power parities.) Moreover, people in the bottom quarter typically work longer hours in more exhausting jobs, and have about 20 to 30 fewer years of life. So, yes, those among whom you live do not enjoy anything like our opportunities to live a full human life, anything like our freedom to learn, think, enjoy, and be creative.
These huge discrepancies are profoundly unjust, and it would be good if many people in the more affluent countries used their much greater powers to change the world toward overcoming such injustice. Unfortunately, this is not happening, though some are trying. Those who have most power to contribute to change also have the least vivid sense of how urgently such change is needed.
So I think your friend is wrong, and wrong on both counts. Being affluent does not mean changing the world -- most affluent people make no effort to promote justice or any other greatly needed or otherwise important changes. And being poor does not mean not changing the world. Think of the Manchester dock workers who helped end slavery. Think of the millions who marched with Gandhi or Martin Luther King. Think of those who denied the US victory in Vietnam. Think of the garment workers in Bangladesh who just won an 80% raise in the minimum wage (from $25 to $45 per month), thereby lifting the spirits and in due time the wages of millions of grievously exploited workers in other poor countries. Ideally, of course, rich and poor should change the world together, toward reducing poverty and injustice, and toward preserving the health and beauty of our planet and its many species. Realistically, I would expect at least as much of a contribution to needed changes form the world's poor as from the world's affluent who, despite their much greater freedoms and capacities, typically find the status quo morally quite tolerable. I won't pass judgment on those who feel they are too poor to help change the world. But I do think it wrong, both empirically and morally, to count out the poor as important agents in human history.