honestly, it's like Canute pushing back the tide to take the approach that a 13yo+ teen can't have Snapchat.
I agree it's a nightmare. However, it is literally how my teens communicate. They don't use any other forum to do so, except occasionally TikTok.
It is also part of their social norms - the streaks etc, snapping back with random, pointless photos. Makes no sense to me, of course, but that's how it should be.
PP are correct. There is potential for much harm. However, I believe that part of our duty as parents is to help teens navigate situations, risk assess and make good choices.
My DD never had a single issue, no bullying, no inappropriate requests or behaviour. All fine.
My two DS (currently 16 and 14) have faced various issues. These have included group chats with inappropriate content (nothing awful, or legally wrong but unpleasant language and general goings on), sharing of images that they shouldn't, imo (nothing sexual, or inappropriate but just not very nice or taking photos of one of their siblings without permission and sharing that and so on), being added to random group chats (that absolutely could have been serious but they saw that immediately and didn't engage).
By far the biggest issue is how utterly addicted they are to it; there is a continuous battle with them to manage their usage e.g. not constantly snapping so they can't use it in the car for example (I want them to talk to me), obviously not at meals either, they have screen limits (this still includes the 16 yo, reluctantly) and no access at all after 10.
I find it ridiculous I still have screen limits on a 16 yo phone but I took them off for about 4 months and it was crazy. He would sneak out of his bedroom at night to get to his phone. He is aware that if he can show the ability to self-regulate, he can have restrictions limited but so far, he hasn't been able to do this.
I'm not in favour of banning it. It's a communication tool, it works very well on that basis. It's fine to say use WhatsApp etc but none of my DC children go near WhatsApp, and if they aren't on Snapchat, they would miss out on events, plans, organised meetups and so on. For some DC, that might not matter but it does for most.
The disappearing messages can be an issue (you can change settings but it's hardly worth it - the other person in the chat can change them back and they will - teens don't want their messages saved). However, I tend to check my youngest son's phone most days, he's aware, and I get a fair sense of what's going on, even with disappearing messages. It's fairly easy to see what might be problematic, and what's not.