Bear in mind that "art" is not just "paintings and poems". Novels are art. Movies and television shows are art. Music (of all types) is art. Games, indeed, are art.
Basically anything that you might turn to for entertainment and aesthetic pleasure is art, and as humans we need it in our lives—both consuming and, in a great many cases, creating.
But many forms of art have always been commercially non-viable. Many if not most of the best-known painters and sculptors from times past fell into one of two categories: those who had wealthy patrons, and those who died destitute.
Why should we say that only those artists whose work meets some arbitrary standard of commercial success are allowed to create art without spending most of their waking hours doing something else, or else having to constantly worry whether they'll be able to live to see another year?