A work is never completed except by some accident such as weariness, satisfaction, the need to deliver, or death: for, in relation to who or what is making it, it can only be one stage in a series of inner transformations.
— Paul Valéry, “Recollection”, Collected Works, vol. 1 (1972), tr. David Paul
I would suggest that it is also never completed for the audience (society) to which it is addressed for much the same reason as for the individual creator.