I'm 38 and I still message friends online. I grew up in a small town in a rural part of England, and part of how I got into webcomics was as a way to connect with people, so I've had a bunch of online friends since my teens, and I'm used to not seeing my IRL friends that often and chatting to them online too. I did my first degree in Japanese, so some of my old uni friends live in Japan now, so I can only really chat with them online.
I don't really feel like I run out of stuff to say, because most of my friends are people I share hobbies with. I'm bad at small talk IRL, so most of my conversations tend to be about shared hobbies both in-person and online.