Bear with me here.
Society is fast-paced. Most people are used to instant gratification, especially when it comes to messages from friends. It probably seems silly to even think about sending a letter when texting is so much easier, but here are a few points that may convince you otherwise.
1. You can give (and get) little gifts.
A hand-written letter in itself is so rare that it's a gift all by itself! When you have a consistent pen-pal, you have something to look forward to when you get the mail, instead of just junk and bills. You can take this sentiment one step further by including tiny gifts in your letters, like tea bags or pressed flowers.
2. You can exercise your creative muscles.
Even if you aren't the artsiest person, writing a letter has the same therapeutic power as painting or sculpting. Handwriting something personal makes you think about how your words sound to a person reading them, and how your handwriting looks on the page. It also gives a perfect opportunity to use stickers, washi tape, or maybe even doodle freehand to make a letter pretty.
3. You can practice delayed gratification.
Don't get me wrong, I love my phone and I am 100% glued to it. It's very important to communicate in a timely manner, and to get information to people who need it. At the same time, I recognize that I get impatient when things don't happen as quickly as they do with strong wifi. Having a hobby that moves at *ahem* a snail's pace, reminds me that life doesn't have to move quickly all the time. It strengthens my patience, and it can do the same for you!
4. You can have a personal conversation by yourself, with company.
Lord Byron said "Letter writing is the only device for combining solitude with good company."
When you write someone a letter, you have the opportunity to reflect on yourself and be vulnerable in the comfort of your own home. When your pen-pal reads your letter, they have plenty of time to write a thoughtful reply and do their own reflecting. You get to connect with a friend while also spending time alone, which is perfect for any introvert or extrovert.
5. You can stay connected, sans "read" receipts.
Texting or messaging is great for quick check-ins, but there's always the added stress of wanting to message back in the right amount of time. If I text back too quickly, is that desperate? If I wait to text back, that's too aloof. And God forbid I have to double text!
With snail mail, the time frame is completely out of your hands, and that can be very comforting. There's a mutual respect attached to letter writing where you both know that the other will write a letter at their leisure and whenever it gets to you it gets to you. If a letter takes an especially long time to arrive, that's just the postal service, nothing either of you can do.
6. You can have a new, unique hobby.
Everybody needs a hobby, and letter writing is good one for lots of reasons. If you don't have a lot of time to kill, snail it's perfect for you. You only actually have to write a letter about every 2-4 weeks. You can definitely carve out some time for that. Plus, you have a permanent cool fact about yourself to tell people. You write letters. Who does that?