Writing someone a letter is a very personal thing and you're creating a memory. Something tangible, concrete, also weighs in on reality. Looking at a piece of paper with your handwrite makes you understand you're commiting to something.
I'm a FOSS loon but the craze of making everything digital is absurd. I've listened to people criticizing others for using paper and a pencil to take down a memo, note or even journaling, when they can do it on their phone.
Is existing so dreadful nowadays? Does the notion of leaving proof of existence scares?