I think that comparisons to most of the world population are irrelevant. Telling someone who is struggling in a developed country that somewhere across the world many people have it worse - this doesn't help anyone.
My hypothetical friend was complaining that he will only inherit $5M from his parents, because they made some bad investments, when he should really be getting $15M.
Does no one have a right to tell that person to stop complaining and accept what they have? After all, how does it help my hypothetical friend that some people happen to be struggling more than he is?
Our poorest people are also our fattest, so it isn't food.
Less than .2% of our population is homeless, so it isn't shelter. And there are state and privately run shelters for those .2%.
Health care is state-provided and free if you have too low of an income, so it isn't health care.
So...what is it exactly?