Sorry if it comes across as an attack on your lifestyle. It isn't meant to be. If you find extrinsic motivations morally suspect, then let me assure you I believe your motivations are entirely intrinsic and pristine.
But regardless, there are such things as trends. It isn't presumptuous to assume that people do things for the social benefits. That's just being realistic. If it builds their social network, increases their status, widens their career prospects, makes it easier to find a better mate... perhaps they should be doing that thing, whether it's running an ultramarathon or doing a 6-hour headstand in a park. What does it matter?
Except that if 6-hour headstands become the hot new thing that every young professional seems to aspire to, I'm going to ask about whether "society" should be glorifying something that's obviously going to lead to neck damage versus, say, a nice 6-hour foot race. That's all.
People will always go to extremes in everything, though. And naturally, some people will see that extreme and feel a strong desire to push further. I simply see nothing wrong with it, regarding exercise, is all. Have a good one!
Honnold probably does it for himself but I agree that a lot of people exercise mainly for other people. They want to look good or impress them. Not necessarily wrong but it can lead to unhealthy extremes.
I think it's a bit presumptuous to categorize extreme exercise as "just to impress their friends". Was Alex Honnold free soloing El Cap just to impress his friends? I doubt it. The same can be said for almost all extreme challenges. Why climb Everest? Why run a marathon? Why go to the moon?
To crib JFK: Because it's hard. Because you can. Because it's there and it's maaaybe, just maybe, possible.
Regarding my last sentence, perhaps I could have phrased it better like this: I would rather destroy my body through hard work by trying to achieve difficult things like an IM triathlon than destroy my body out of apathy and sloth and gluttony. Either way, if all goes to plan, my body is gonna go to shit at a certain point anyway and I can't do anything about it. And then I die. So why not try to have some fun?