They saw how to change their lives and family, and they saw business opportunities, which is why they have developed to where they are today.
Moreover, those people already knew that remaining unchanged would eventually lead them to be unable to maintain their previous circumstances, so they continuously made changes, carefully thinking about what to sell and when it would be suitable. They adjusted their actions according to the changing times and people's preferences. Their method is quite correct because they fully understand the changes of the era; everything changes with time, not only society but also more so people's preferences. Perhaps, initially, people only wanted to satisfy simple life needs, but as time passes and their living environments change, they may want to enjoy more. This is why these merchants are considered very smart because they find the right things to sell at the right time, naturally leading to great returns.