People have different preferences, I take my notes on multiple places of different formats so I understand the appeal of a digital one and a written one. It is rare for me to take notes but the ones that I want to keep more permanently are written. Day to day stuff are typed up and checkmarked once completed.
For a lot of my job a lot of parts have to be hand written and there are no excuses for typed up stuff, the same goes for my colleagues, for people in other departments in my company, for my clients, for the client’s client, the list goes on.
Your argument that if you already own a phone a pen and a notebook does come at a cost, yes it does, but your phone has a phone plan right? So you’ll pay monthly for it? Unless you just have a phone and rely on WiFi connections?