I’m going to go on a limb here and say that the era of the file is over. I think that a creation is really a combination of components. Look at a Photoshop “file.” What is it really? It’s a collection of fonts, images and layers of edits and other things taken in from other places, composited together. It’s a collection. All those components, those ingredients of that composition both still exist in their original form as well as their combined altered form, which is ultimately the composition you’re making in a PSD.