Not necessarily; however, by having a Kakao account in South Korea, you have access to a wide variety of tools, apps, and features available in the Korean market. For example, Kakao T for taxis (like Uber), KakaoTalk for communication (like WhatsApp), and KakaoStory for social media. You will find that almost every person you meet in South Korea will be using KakaoTalk for communication, so it would make sense to have a Kakao account if you are living in Korea.