I think that the belief of pen and paper being "natural", is a weird idea. We have less than 7,000 years of history with pen and paper, closer to 50,000 if we include cave paintings. Far as evolution is concerned, that is a pretty darn short. Our understanding of writing - and computers - arises from an incidental application of our intelligence, not the other way around.

I am a scientist myself and I cannot see how you can solve maths and physics problems on a tablet. Maybe I am incompetent and lack the imagination but the physical limitations of these devices just make them cumbersome at best. Again I am not arguing against tablets computers etc. Just that some things are better learned with pen and paper. There are far fewer distractions and you get a much better picture when you have 3 pieces of paper in front of you with all the steps you took to get to where you are now in your solution than swiping back on the tablet. I am obviously biased but it just makes more sense to me.

Writing an article absolutely digital I would never argue against it. But actual learning is better analogue in my opinion.

And then there are the issues you mention about forcing people to use a certain brand for their education. Pen and paper is for everyone. Easily available and ready to use. I can see your argument for textbooks and here it is where a tablet could be useful (provided is distraction free). Load it up with textbooks and go. But even then my bias makes me skeptical. There are mental mechanisms to remember information from books. One can remember the placement on a page, the place in the book. In a digital version that constantly changes depending on how you read that.