When you research Wing Chun you will see many people practicing either Chi Sao (Sticky Hands / Energy Hands), or the Mok Yan Jong (the wooden man dummy). These two things are so prevalent it becomes understandable the average person believes that is what Wing Chun is.
It is not. These things, the Mok Yan Jong and Chi Sao, are tools. They have a cool factor that causes them to be displayed more than any other thing. However, they are used far less than the newcomer believes.
Wing Chun training is the relentless practice of drills, rising up to sparring. Yes, the Mook Yan Jong, Chi Sao, and forms like Siu Lim Tao, are part of that practice. Again, they are only tools, which occupy probably less than 30 percent of your training when taken as a whole.
These tools are some of the best at creating a solid Wing Chun foundation, as well as an expanded knowledge. This may be another reason they are featured so predominantly. However, in the end, the constant application drilling is what will make your Wing Chun usable.
We all do what we practice.