Ah Tao in the movie shows that she can achieve a happy life with very few material goods, instead focussing on the basic functions of living and human connections. When taken to the nursing home, she reassures the caretaker that she has very few belongings, showing that she can live well without materialism, consumerism, and other features of the growth economy.
Ah Tao from "A Simple Life" and Mija from the movie "Okja" are similar because they both live a very simple life but are still satisfied.