What is KCS adoption?

Could you please elaborate on the concept of KCS adoption? What does it actually mean? How does it differ from other forms of cryptocurrency acceptance? What are the key factors that influence its widespread use? Is there a specific metric or set of indicators that can be used to measure its adoption rate? Additionally, how does KCS adoption contribute to the overall health and growth of the KuCoin ecosystem? Finally, what are some of the challenges that may hinder its widespread adoption and how can these be overcome?