Humm lets see if I can make sense.
A material is nothing more than a visual representation of a text based syntax that describes the nature of the material. Is it metal, is it wood, is it plastic, and by its self is as about as useful as a car with out tires. Sure you could sit in the driveway going vroom vroom but you not going to get very far very fast
So in a way the materials available for use or for sale are more useful in this state as a means to showcase the crayon on a sphere and to help window shop for the perfect shade of purple.
To be useful.
One should be able to take any material and apply it as a composite as a mix or blend as to the final output with in the same kind of edit environment, in app, as say a Photoshop, Illustrate, or any other option that has been out for years.
Now some would argue that by wiring up a few wires one could create any kind of result that they are looking for but to put it in content artist terms that would be like telling a web designer that that can’t us the wysiwyg and have to do everything using notepad. 