I use a softcover notebook to think things through, but my phone is easier for details I might need to find later. Short reference notes are where the two overlap, and copying them over feels like busywork. I'm trying to decide which one should hold onto those.
The notebook can stay the original for notes you wrote to think things through. Move just a short takeaway to your phone when you might need it away from the notebook, rather than copying a whole page for one searchable detail.