Curious how someone could have most helped you at that time in your life if you don't mind sharing.
It's hard to fix every cause of homelessness, but providing shelters is pretty easy.
* nobody wants a shelter built near them * even if it does get built, it's often women/children only
and the second bullet point isn't (afaik...) just sexism or anything, it's just picking risk categories. Consider all the following like you were an insurance company trying to appraise how costly it is to do business with a group of people: Apparently homeless men are, collectively, more expensive to shelter than women/children because they're plagued by more expensive issues - more violence, more drug issues, etc. So homeless shelters frequently can't afford to operate if they try to shelter men. So it becomes an issue of "women/children only" or "it's literally too expensive to safely run the (both-genders) shelter to be feasible".
When I approached He asked for change, which I didn't have, so I asked if he wanted the remaining half of my sandwich and iced coffee instead. The sheer joy of his reaction as he took the sandwich and coffee is something I'll always remember.
The way in which you wrote this could be misinterpreted, so any clarification would be welcome: did you then or do you now feel as though someone is obligated to help you? If so, who and in what ways?
Want to make sure this part of the comment is also highlighted because big homeless shelters can be really difficult, scary, and even dangerous places, even when there are beds available, and so unhoused people have to wrestle with whether it's safer/more desirable to sleep outside rather than deal with all that. And that's not to mention all the cumbersome rules and religious proselytizing they might have to deal with in shelters. Warehousing people is not a good option.