It is unlikely that painting by numbers will ever “rule the world” in the sense of becoming the dominant form of art or the only type of creative activity that people engage in. While painting by numbers is a popular and enjoyable activity for many people, it is just one of many available forms of art and creative expression.
Moreover, art is a highly personal and subjective experience, and different people will have different preferences and interests regarding the types of art they enjoy creating and viewing. Some people may prefer traditional painting methods, while others may enjoy sculpture, drawing, or other forms of creative expression. It is unlikely that any single activity or medium will ever be able to appeal to everyone.
In summary, while painting by numbers may continue to be a popular activity for many people, it is unlikely to become the dominant form of art or the only type of creative activity that people engage in.