With so much note taking apps nowadays, I can't understand why does anyone still write notes with pen and paper. You need to bring the notepad, book or that paper to retrieve that information, and most of the time you don't have it in hand. While my phone almost always reachable and you carry when you go out. For those still like to do handwriting, there's many app does that and they can even convert it to text notes.
So, if you still write notes with pen and paper, why?
One thing paper helps me with is free-form thought externalizing.
When you limit yourself to text, markdown, or sometimes even a digital pen/drawing app, I feel like it requires a bit of effort to use which allows ideas to slip from my mind.
With a pen/pencil and paper, I can write, draw, and connect about as fast as I can think. I can crumble the page and refine the idea over and over until something I like is there.