would something like an ipad + apple pencil not bridge this concept? The usage of pen & paper with the addition of the digital world; OCR, tagging etc.
It sounds small, but "taking a second to select a new brushstroke from a list of options" is exactly what OP is talking about in terms of raw creation vs synthesis.
There are definitely advantages to digital, but there's no denying that, by adding a middleman between yourself and the world, you lose raw experience.