Possibly his ego is fuelled by giving to others. Everyone is different. It probably makes him feel happy. Obviously if they don't give anything in return and show fake appreciation, then it's a bit false. But if he enjoys it and views it as him taking care of some underprivileged people, then what's the harm?
Obviously, it would suck if they came over to him one day and he didn't get his wallet out and they immediately walked off and stopped paying attention to him.
It is possible that the act of giving brings him joy and he wants nothing in return, other than a thank you.
Some people even find joy in just making other people happy. I think it all depends on how you're raised.
One problem is when someone like this encounters another person who is simply an unhappy person. They can be quite upset seeing another person being happy and bringing joy to other people's lives.