Here’s the biggest reason: we are evolved from savannah primates for whom the ability to make eye contact and hold it was a signal of “you can trust me, I’m not about to bite you.” Paper and pen don’t signal “I have decided to break this evolutionary/social contract” in the same way a phone or open laptop does.
I help mentor a lot of young people in early career and their generation with a phone is an excuse for an x-er/boomer interviewer to punt them waiting to happen. It’s career and comp limiting, right or no.
Also if one finds a taken note is missing something, contact the original party. A conversation that begins with: “you got me thinking about this more deeply and I think I may have missed something…” is the key to mentorship, advocacy, and growth.
In short from a transcoding of bits perspective, other media may be better. But for those they acknowledge human constraint and opportunity a nice notebook and (a cheap shill from me) a Lamy Safari medium nib fountain pen will do you quite well.