Here's a comment to When Paper Beats the Paper on Hacker News.
The digital medium often strips human expression when capturing input.
Devices such as the Apple Pencil are getting better at capturing pressure and highly-detailed paths, which in turn are encoded as vectors and can gather information that is lost in physical mediums, such as coordinates, drawing order, and temporality, even capturing things not present on paper such as hover gestures and pressure.
Yet it's common practice to reduce gestures and clicks to points, lines, or curves - two clicks from thousands of users in a CAD environment may output the exact same line from point A to point B - which often forget about the expressiveness of pencil strokes on a sheet of paper, features which could be used by machine learning algorithms to discern intent in the input of different users.
"Burning through pages" is a great way to put it. No need to worry about sheets of paper lying around or scanning and document what you do. It's all there. I especially like that, with the "fineliner," strokes are vector polylines (as opposed to shapes in other brushes) that can be used later to simplify, redraw, and animate documents.