The "whole of human experience" is a formal concept, since you surely don't believe any of us can informally experience it. Societies formalize it by collecting data and debating theories. And big human stories are the ones which are difficult to intuit.
There are those who do nothing more than collect information on homeless people, documenting them for various organizations or gov't agencies, sometimes paid. They are doing the fundamental work of demonstrating a phenomena whose scale would otherwise be belittled or denied. Some would say SF is actually pretty nice, with only a small homeless population.
When experiences disagree with each other, how should we move forward with discussion? With personal experience or with data?