They probably do, but I haven't used Facebook at all aside from a brief period in the 2010s. If they organize on Facebook, and I don't have any other way of finding out about them or otherwise contacting them, I just don't bother.
I am willing to accept some inconvenience in order to be aligned with my goals, which I am learning puts me very much at odds with the average person.
Also, if you don't have Facebook and want to go to this running club you would be forced to actually befriend someone to such a degree in the club that can keep you updated that has Facebook. It can't just be the "convenient" disposable Facebook relationship.
For me, without social media I pretty much miss out knowing about all the local art shows that I wasn't going to go to even if I did know about them. I don't get the invite to the friend of a friend's dinner party that I would have made up an excuse for why I can't go. I also miss out on seeing pictures of all these events that I didn't find worth my time to see with my own eyes.
We have really distorted the meaning of inconvenience to have something to do with the lack of high volume, unsatisfying, shallow experiences.
As if having sex is an "inconvenient" type of porn.
The best part though is I have actual experiences that aren't mediated by the judgement if the experience is worth someone else knowing about the experience the very moment after I have the experience.
I am willing to accept some inconvenience in order to be aligned with my goals, which I am learning puts me very much at odds with the average person.