Onur Cobanli explains:
Design without purpose is decoration. Beautiful visuals lacking clear function serve no real user need (apart from emotional and aesthetic needs which are important). Good design solves specific problems while purely aesthetic design merely pleases eyes (Which is also super important). That said, art has its intrinsic value and serves an emotional need, so design without function is art, and is still valuable. Decoration is valuable. We cannot say design without function is art, because art is a function, it is aesthetic and emotional function, we need art, we all need more art.