To begin, extended family give a strong bond to one in the extended family so help one to be able to form a reliable and psychologically healthy mind. In modern society, people are more likely to feel lonely and isolated as people more focus on their lives and busier than before. It causes many social issues including increasing suicides. But, in the extended family, people can feel more they are strongly supported by their families. For example, when I was young, I usually lived only with my parents and an older sister and when I came back to home from school, most time the home was empty as both my parents had to work and my sister was in out for studying. Therefore, many times I had to eat by myself and felt lonely. But when my grandparents stayed for months in my home, I was able to eat and talk with them after school. With living them together, I was able to feel more supported and to get more along with my friends in school.
Moreover, people can nourish their thoughts as they live with their grandparents. Grandparents lived in a different history and therefore they have different thoughts with not only myself but also with my parents. Therefore, people can broaden their eyesight to the world by deeply interacting with their grandparents. To be specific, my grandparents experienced North and South Korea war back then in 1950. They make me heard about stories they and their friends experienced in the war and I was able to deeply understand the history and able to have better eyes to see the real world. If they weren't, I would think only based on what described in my books in class and would not develop my thoughts further.
To sum up, extended family have many merits as it gives strong supports and warmness to its members and also makes them have more developed thoughts to the history and the world.
For these reasons, I firmly believe that the extended family is important today as before.