As one of the earlier posters said, I think tons of people wouldn't run if there was no social media, or they weren't able to talk about it.
I don't have a problem with people sharing their running with others (though as someone over 45 it utterly baffles me why anyone would want to take a cell phone with them on a run, constantly stopping to take pictures of themselves, but each to their own). But I do think that too many (younger) people run simply because of their innate narcissism whereby they have to seek external approval or "likes" from others before they can derive enjoyment.
I'm the opposite, and expect many on here are the same. I run most days, and don't tell anyone about any of it. No strava, no log, no photos. I've been running 50-100 miles a week for about 20 years. Even been on holidays to the mountains alone for a week of running trails, and my best friends (who are non-runners) wouldn't even know about it. Guess I'm an introverted kind of guy.