Words live and travel independently of the medium they are created in in a unique way. If you look at other forms of art: a sculpture is made of a particular material and is inseparable from that. Drawing makes use of all kinds pigments and dyes and pixels that set apart an oil painting from a watercolor from a digital drawing. The properties of those substances are apparent in the image. Music—has hundreds of different instruments.
But these words? They are published on the internet, so clearly I put them into a computer file at some point. But did I compose them directly in a text editor? Or work them out with a pen and paper first? A pencil? A typewriter? Did I go to the beach and arrange these thoughts with a stick in the sand? You on the other end are probably reading on your own digital screen, but maybe you printed this out. You could be using a screenreader. These words, this message is totally opaque to all those possibilities.