The homeless are unique and in and unbelievably precarious position.
I used to do homeless food runs with my local parish, and I was near shocked at my first encounter with them. Why? Well.. I remember being a kid, and growing up very skinny. Legitimately probably weighed 30kg soaking wet, and would often hate eating. And my parents would say "If a homeless person was here, they would eat whatever you put what's in front of them".
So I was shocked when I saw many of them rejecting whatever food we had provided. Some times hot food (rice or pasta dish), other times sandwiches. So I became, not so much judgmental but more annoyed - it's like hey dude, I am here to help you out.
And then the reality hit me. Some of these homeless people were rejecting, for example, sandwiches, because they had crust. And then one of them laughed at me when I offered her a sandwich (not in a condescending way, but in a "I wish!" kinda tone). And when she laughed, I knew why she was, and countless others had rejected them. They had barely any front teeth left. They struggled to eat and break down certain foods because things like hygiene and dental care are things they can no longer afford. It's an incredibly sad situation.
Furthermore, many of them suffer from mental disorders of some kind. So don't take it too personally - many aren't overly thankful from their own shame and pride. They still cannot believe or get over the fact that they are in the position they are in. Many of them own it, others - well... it hurts them to their core.
Also - as for the thread - there are many many MANY well off people who do things in this space, that you just don't know or hear about. Why? Because they don't want their name up in lights. It was not until after Elvis died, for example, did they realize how much he gave to charity.