Growing up as a kid and whenever I always met my grandparents, my father would always tell me to hold their belongings, show affection, and respect them. As a child, your brain hasn't developed certain cognitive functions until it's consistently drilled to your brain. This was something my father would always try to teach me. Filial piety is known in Confucianism ethics, which is a virtue of respect for one's parents, elders, and ancestors. A concept that is drilled onto you from beginning if you're Chinese or most Asian cultures. I've had my fair share of confusion in the past understanding this concept because I was born in Hawaii and there were many different cultures and how our generation were slowly changing. As I grew older, I realized the sacrifices my parents have made to give me and my sister a better life, working 12+ hours every single day, managing a restaurant was not easy and doing that for almost two decades. One day, I decided to take over the responsibilities of groceries, chores, dinner to lighten their workload. Since I was 16, I have been buying groceries, cleaning the house, washing the dishes, and making dinner for my family. This is something that I have also taught my sister because I believe filial piety supports warmth and harmony, with beneficial effect on one's personal growth and interpersonal relationships. Your parents will always sacrifice their time for you and I'd like to think the same way should be applied. They take care of you until you're old enough to support yourself, you take care of them when they become old and struggle with daily activities. I don't see it as a repayment of a debt but as a sign of showing my love to my parents and being thankful for always being there for me. 

Money is not always the case in this Confucianism concept but the act of caring for your parents. I understand that many people also have different perspectives. I also would not want to make this a moral responsibility for my future kids but a voluntarily choice.