I am happy to say I've recently discovered salsa and am dancing several times a week.
Latin dance and West Coast Swing have much younger demographics than country dances, are danced worldwide, and in both quite sophisticated and in street styles. They fit precisely the embodied, highly social, and subtly sensual (or not so subtly in the case of bachata) functions the author misses. Can highly recommend.
The Scottish Ceilidh, the Irish Ceili and the many Platford and Regency style balls hosted by folk clubs and dance groups keep these very much alive.
When I travel I always take my dance shoes and find local groups to drop in on and am always welcomed with literal open arms.
Sadly in my 40s I am one of the younger attendees of these events. Which is a tragedy for those of us who already love the culture and those who will never experience it.
I hope there's some popular movie or TV show that makes it cool again, and injects some fresh blood. Otherwise, it's just going to die, and that would be a loss.
(There's also a contradance[0] about 30 minutes from me. That seems to be having more success attracting young people...?)
A friend of mine used to host Contra dances done to techno with nightclub like strobes that were very popular with the university students nearby.
But seriously, you're right that they don't always look like they'd be welcoming. Most folk clubs tend to skew older and that often means conservative, though my experience is that most of the old folkies now were all young hippies once and honestly they are more likely to attend a rally/march than a middle aged professional with a full time job and family...
The rich social events and intellectual discussions of America’s past have turned into depravity and crude dancing, and curse filled lyrics.