Fewer than half of all teens in America use Facebook, according to a new teen survey from Piper Jaffray. Meanwhile, 82% of teens are on Snapchat, the survey found.

Snapchat (SNAP) is the clear favorite among Gen Z, but it hasn’t always been the case. Last spring, Snapchat beat Instagram as teens’ favorite social platform.

“It’s not clear to us that teens growing up today feel the need to have an eventual organized network,” Piper Jaffray analyst Sam Kemp told Yahoo Finance.

“Facebook is not becoming obsolete by any means, but the lack of adoption early on in the life cycle suggests that there’s just a declining utility of the network. That’s going to prevent user growth beginning in 2019,” he added.

Teens aren’t on Facebook. But not because their moms are.

One common argument is that as older generations adopt the platform, the less inclined teens are to engage with it. But is the “mom indicator” really the death knell for any new innovation?

Kemp highly disagrees with this premise. “Teens don’t care that their parents are on Facebook. They just won’t friend them … or accept their friend requests,” he said.

It comes down to how teens want to communicate — namely, through photo and video. Kemp points out that photos and videos are “not just easier to consume and watch but also to produce” than written posts — adding an extra layer of engagement.

And while Facebook (FB) has been trying to penetrate the video creation market with its own Stories feature, teens don’t need it when they have Snapchat at their fingertips.

Ultimately, though, Kemp said Facebook is not as addictive for teens as Snapchat. While Instagram has become a media platform where teens can consume and interact with influencers, Snapchat lets you connect with a narrower network.

“There wasn’t as much of a social fatigue. When Facebook first came up, it was the only option for new media formats. Now, the alternatives are more gratifying for teens.”

But what’s next after Snap?

Piper Jaffray’s survey allows teens to write in their own responses if one of the social media networks listed in the choices wasn’t their favorite. Of the 6,100 teen respondents, only a handful filled in the blank.

Before Piper Jaffray made Snapchat an option, respondents started to write it in as their favorite social platform, beginning in 2014. Kemp said there is no clear up-and-coming player these days.

“I think you’re going to see a continuation of the trend that you’ve already seen. I have a hard time thinking there will be new entrants when it comes to social. There’s a lot of direct messaging and broadcasting in both public and private models. And the combination of photo, video and text are covered with existing platforms,” he said.