Art is also about entertainment and beauty and controversy and yes, even sex. But invention is definitely a major component. We all need innovative solutions to everyday challenges. Admittedly, invention isn't the exclusive domain of artists. I know people who invent every day.
Single parents come to mind.
But even these creative thinkers could use art's lessons to become better problem-solvers. But in the meantime, you get to live a fuller, more satisfying life. You get to be the creator in some deep, fulfilling way, by solving a problem with your own personal solution. As humans and as artists, we have to make mistakes, take risks, produce a surplus to get what we need. As any scientist will tell you, there's no way to tell which research will be fruitful without doing the work.