Art is a business. Art is self expression. Art is communication. Art is a cultural and social form of expression. Art is a business.
Expression implies an audience.
If the artist has no audience then the expression is in a vacuum. If an artist wants to communicate, there has to be an audience. Art for art's sake is fine but it servers no purpose other than self gratification if it is not seen, and hopefully, purchased. So, in order for the artist to become a successful artist, they must also become a successful businessperson. The basics of record keeping, time management, contracts and marketing must be learned and practiced.