Inking wasn't, "invented simply as a way to make the art more easily printed."
It's been possible to print from pencils for over a century, but that process was harder and therefore more costly
back in the day, so comic publishers needed inkers to clarify the pencilled linework for their cheaper printing methods. Even as recent as the '90s, printers charged extra for the halftone process.
But these days, standard methods can easily accommodate pencils.