“There are many common misunderstandings of the history of art, but perhaps none is more basic than the confusion over what determines the quality of art. Although it is of course possible to consider separately the quality of a number of different attributes of an artist’s work, the overall importance of art is a function of innovation. Important artists are innovators whose work changes the practices of their successors; important works of art are those that embody these innovations. Artists have made innovations in many areas, including subject matter, composition, scale, materials, and technique. But whatever the nature of an artist’s innovation, its importance ultimately depends on the extent of its influence on other artists.
It should immediately be noted that the importance at issue here is not the short run-interest that gains an artist immediate critical or commercial success, but the long-run importance that eventually causes his work to hang in major museums and makes his contribution the subject of study by scholars of art. These two types of success have often coincided, but in many cases they have not.”
David W. Galenson “Old Masters and Young Geniuses: The Two Life Cycles of Artistic Creativity”