There are many organizations providing 中国語 classes. However, they often emphasize theoretical knowledge, which means you're not always prepared to put what you learn into practice. In addition, the teacher's time is split among many students, making it harder to get personalized attention and help.
By contrast, one-on-one learning focuses on your individual needs. Your tutor is able to tailor the lesson for each student. For instance, if you want to learn 中国語 for travel, the tutor can incorporate relevant lesson content that you can apply on your upcoming trip. Add to that flexible scheduling, and it's easy to see why one-on-one learning is the perfect match for busy life.