Maintaining a circle of friends is a pretty weak justification for social media use. Many of my friends and I don't use social media at all and we have zero issues coordinating events. It sounds like the real issue is that you didn't value the connection to your friend enough to reach out to them. SMS and phone calls are still a thing.
Reddit is definitely one of my main browsing vices. I've found that the only way for me to use it somewhat responsibly is to make use of multireddits. However, I can't seem to use it responsibly on my phone for some reason. I think it might just be the inherant nature of the form factor as I don't seem to have nearly as much trouble when I use Reddit on my PC, but having a Reddit app on my phone is a surefire way to kill my productivity.
I have always seen my PC more as tool to actually get work done and my smartphone primary as a communication and entertainment device. I think we can all agree that it is very difficult to get actual work done on a smartphone, so perhaps the form factor itself is what makes me more inclined to mindlessly browse.