A Piper Jaffray survey released this week showed that, for the first time, more teens prefer Twitter to Facebook as their go-to social network. It prompted a number of news items touting the triumph of Twitter over Facebook.

Many observers missed the story, however. And I can see why they did. The decline in Facebook use by teens and young adults has been well-documented over the last few years. Now that the tipping point finally may have been reached, there was a natural impulse to focus on that as the key takeaway.

But while Facebook’s decline among young adults is stunning — nearly half have downgraded it in just the last 12 months — Twitter hasn’t been the prime beneficiary. Look at the chart above, and you’ll see that as Facebook has lost favor among teens, Twitter has remained pretty stable.

Instead, the slack is being taken up primarily by Instagram and “other.” What’s “other”? Probably some combination of Vine, Snapchat, Pheed and other newer social offerings.

It’s odd to think about it this way, but for teens and young adults, Facebook and Twitter may be turning into the Oldsmobile and Buick of the social media world.