I don't agree with this article. I write hundreds of lines of notes each day, as a part of my coding and work routine. I do it all digitally, in Visual Studio Code, as pure text. I think, as long as you can write fluently on a keyboard, and as long as the writing and typing itself does not steal CPU cycles from your brain while you're doing it, it works just as well as handwritten notes, and, I would wager, probably even better, as you're able to write quite a bit faster on a keyboard than you are when you're writing with a pen.

As for the "slowness" of the writing being a point in itself, I don't think that's true. I achieve the same by editing my text as I write it, pondering over my wording, to make sure that I communicate (to myself, mind you) the precise intent that I'm going for.

I think the fondness for handwriting is mostly based on romantic notions, for lack of better words, predicated by our closeness in time to a period where handwriting was much more common. We think of it as the "original" way of writing, and the most "pure" way of writing. Personally I think jotting down text notes on a keyboard is just as "pure", and I don't really think that there are any extra qualities associated with handwriting, as far as learning and retaining information goes.