The equation is very simple for all forms of creation. The act of creation has real value and should be compensated for (in our society this means money, but this isn’t a rule). Once created, easily replicable items are only worth their cost to replicate and all other value is artificially induced. We compensate the act of creation fairly by any of the means i mentioned before and then all other costs are material and labor. This is fairest to creators although you will see less ultra wealthy artists, this will leave more wealth potential for artists with smaller starting resources.
Also, Art and knowledge are inseparable and this is obvious when you see how a scientist crafts their knowledge into stories and artists weild their medium as engineers.