They do things for me all the time - we have a family compound and someone is always cooking something which they offer me all the time. They take care of anything that I might need. They take care of the dogs when we go away. Yes, I contribute financially which is very easy for me. I like them and want to see them have a good life.
What are you not seeing? When you live together with a family in a communal way, that is assimilation and integration. We all help each other in any way we can. When my wife's dad was being diagnosed, his life imminently in the balance, he left medical decisions to me. Though it was a responsibility I did not want, he trusted me more than his own or anyone else's judgment...
There are rewards of closeness that you may not see. And if you are not the giving sort, they may not be there for you. This is not necessarily the case for others.