that's not the appeal. Snapchat is coveted by it's users because of ephemerality. It grew in reaction to your parents being on fb; in reaction to public, permanent social communication. The users love it because they think it's more authentic - that they're not rehearsing for a contrived selfie or food porn. It's cool cuz they're shooting the shit and not going for likes, and no one outside their sphere is gonna see it.