I find his dismissal of iPad writing to be unconvincing. He talks about how we have calibrated our writing utensils over centuries to involve the proper amount of friction, and how that knowledge goes out the window when you're writing on an iPad.
That may be true, but it's not like you can't just re-acclimate to the experience of writing on an iPad. Most people don't handwrite much, period, so if they start handwriting again they're going to have to have an adjustment period either way.
I personally would think that the the benefits of digital writing (searchability, portability, infinite canvas, handwriting cleanup, digitization) would outweigh his friction quibbles. I personally don't find it to be tiring to write on an iPad, even without a screen protector (which some people use to increase friction). Also, e-paper devices tend to have more friction-y feedback, but he doesn't address this at all when dismissing all "gadgets" outright.
My issue with the iPad is that it just does not have the fine-fidelity or response time of real ink, and it's not something that never fails.
It's so frustrating to be so pregnant with an idea, to open ones iPad, and to find out the battery is low, Procreate isn't working, the Notes app is confusing to navigate, oh no you're writing but your palm has slid on the screen, etc.
I've spent a lot of time searching for a digital alternative, but IMO we're at least a decade away from digital handwriting being even close to on-par with paper, even ignoring friction and feel.
Friction is also variable, with pen and paper type. Although the iPad is a bit too slick, it gets very fatiguing (I did most of my HW in college on the iPad)
I have a "paper-feel" screen protector and a metal nib on my Apple pencil. The combination provides a comfortable amount of friction for me, and the fact that it's matte cuts down on reflections.
iPad is terrible for hand-writing. It's (relatively) heavy, so you can't hold it and write on it. It's slippery, and the friction between the pen and stylus is bad.
The pen itself also produces gigantic strokes.
The study he cites is also specifically using digital pens
> Brain electrical activity was recorded in 36 university students as they were handwriting visually presented words using a digital pen and typewriting the words on a keyboard
kinda funny.
It's also not clear from this study that there is actually any benefit to "more brain activity". Of course doing more complex motor tasks requires more brain activity but nobody guarantees that this helps with remembering things.