It never ceases to amaze me that frequently there seems little planning for succession.
We were once beginners and have now moved on, but still learning. New beginners are needed.
Tango seems to come in fits and starts caused in no small part by what's popular in the media. Periodically, tango shows up in some film, TV talent show, or traveling spectacle. This sparks popular interest. A bunch of people learn tango as a result.
Time passes.
Those people improve as they take lessons, attend workshops, practice, and dance. Through the inevitable course of getting older or changing interests, these stalwarts become fewer and fewer in number. Those who remain grow skilled . . . and often snobby, because they don't want to share the floor with people who get in their way and/or disturb their preferred aesthetic.
Eventually, someone counts heads and raises concerns about the death of tango. However, they rarely do anything about it. Instead, some totally new media phenomenon rekindles the flame. If the style presented as "Argentine tango" is very different from the one that's dying off, there's a clash of old vs. new, usually with cries of "It's the end of tango as we know it!"
Yet tango has survived for more than a century, most of that without the aid of mass media to popularize it. It seem unlikely to die out. It'll just change its look. Most people talking about the end of tango are talking about the end of tango
as they know it.
Around here, we have lots of new tango fans who've dropped the "man/leader, woman/follower" tradition, introduced fusion elements (especially with blues dance), created more free and outdoor events, and so on. Tango is still growing. It just isn't the practice of male-female couples dressing up for evening milongas that's growing.
What's bizarre is mostly that tango fans are more aggressive about their traditions than fans of other dance styles. My mother is thrilled that what she calls "rock 'n' roll dance" is back. It's called "swing" (she claims nobody ever called it that), the people dancing it don't dress like she did back in the day, and there are new moves. There aren't many 1950s- and 1960s-style dance halls with live music any more. But the dance is a legitimate descendent and she's just happy to see it.
Whereas tango people get themselves twisted in knots when they see change.