Great art - or good art - is when you look at it experience it and it stays in your mind. I don't think conceptual art and traditional art are all that different.
In the 1970s and 1980s there was so little decent fiction for young people but we're now in a golden age that shows no sign of fading. Philip Pullman J. K. Rowling Lemony Snicket are only three of the best known among a good number of equals.