My anecdotal contribution:
I always took notes on paper, even though I never even read them. I have trouble sitting still and get bored and distracted very easily, so having something to do with my hands helped me pay attention in university. Doing the same on a computer would mean I would tab into something else and get distracted.
Note taking is similar, if I write something on a piece of paper on my desk, when I get fidgety and move around I'm going to see it. If I wrote it on my computer, it'd be buried and forgotten behind my 20 browser tabs, mail client, editor windows, terminals, etc, and that's if I remembered to open it the next day.
Having a whiteboard on my desk made me way more productive at work. So I would think the reasoning is less deep, it's more that there's less distraction on paper than on a computer.