1. You can read a wider variety of writing.
2. You develop a personal style which is yours and yours alone. It can become a part of your identity and writing can be a huge method of self-development.
3. A handwritten letter is worth more as it takes time and care to craft. People value this.
4. Your grandchildren (or children) can pick up your old journals, diaries, notepads, and any other thing you've written and get an idea of your thoughts, see what you cared about or maybe you left them a message for when you were gone.
5. It is much harder to censor a letter than something you put on social media.
The value is there for those who wish to take advantage of it.