Whilst I completely understand other posters views, I also feel differently to most on here. My almost 16yo DD has managed her SM really well and uses Snapchat and TikTok all the time. We discussed and continue to discuss SM from y5 and she had them all from y7.
From reading posts on here it seems like not everyone is familiar with the apps themselves. I don't use any of them personally but know how they work. As a social worker, Snapchat seems to cause the most problems and with privacy settings on these are very unlikely. The only people seeing men masturbating haven't locked their profiles down. My daughter can only receive snaps from people she knows and has always been very sensible to not add people she doesn't.
I used to do phone monitoring and have always encouraged a very open dialogue. Consequently we have a good relationship and she comes to me with any problems she has on or off SM. SM is her world and learning how to manage it well is a skill.
Going against the grain with TikTok too....private profile and privacy settings on again and although there are definitely things on there that aren't great, on the whole my DD and her friends use it very creatively and have had great fun over the years lip-syncing, creating dances and using all the editing features.
The thing I've always worried most about is my daughter downloading things in secret without my overview or advice and getting into a situation she can't handle and feeling that she can't tell me in case I'm cross or don't understand. Keeping the dialogue open has been my priority and my approach has been to reduce the standoff "hard no" situations. Eg. When she first mentioned Snapchat my initial thinking was "over my cold dead body no!" but instead we had a conversation where I said "I'm worried about xyz happening..." and she researched privacy controls herself and came up with the idea of me monitoring. Sometimes these conversations have resulted in her deciding she's not ready to handle those things yet and other times she's taken on the responsibility of doing what she can to reduce the risks and knows she has me to come to for advice. She often asks me for advice about situations her friends are in too and I am seen as an approachable parent. I am far from liberal and have plenty of boundaries but they know I don't overreact and will help them problem solve.
Having said all of this, I definitely understand the worry and can see why some parents are banning it. Just wanted to present an alternative view
At the end of the day we all worry about our children and need to do what we think is best to support and keep them safe.