There is nothing as comforting as knowing that there is someone near you that will help you out if you get stuck in a pickle. This, at least, is the culture in America today. While it was not unusual for many generations of families to live together in one place, it is now strange to do so in the USA. Thus, it is only those who have less money who tend to live near their families. It is nice to both have and be able to give a helping hand now and again.
People that are considered low income will often stay closer to family because it provides a sense of help and security when needed. An example would be if daycare is needed, low income families rely on other relatives to help more to prevent paying for and out of home daycare. Some people that make a lower income may also have to reside at home with their parents longer in order to save money to buy a house on their own or even just to get stable for themselves.
Yes, having a low income forces people to live closer to their parents. In some cases, even college graduates are unable to afford moving out on their own and may even continue to live at home with their parents. Others who are poor or underemployed may remain living closer to their parents so they can have help with such needs as child care and other things.
Having a low income has a number of disadvantages, one of which is that it is not easy to move away from the support of your parents or the community that you grew up in and supported you. Parents help their children in many ways after they are grown, and living far away makes this more difficult.