And don't make the mistake of thinking Snapchat is just about nude pics. It is mostly used for saying things you want to disappear rather than have everyone reread in the morning.
As soon as people like me know, they move on. The day that professors (me) cops (old people) and parents (very old people) start noticing a platform it's time to switch. Some of my students are using services more popular in Asia. But many, particularly females, simply aren't sharing information about themselves as they might have 5-10 years ago. The novelty is gone.
So what are they using instead? Whatsapp? Other messaging app? Instagram?