You have it backwards, it’s not trying to catch my children doing bad things (though there is that benefit too). it’s more about ensuring that other people are not doing, or trying to do, bad things to my children.

I trust my own children but you’re right that I cannot guarantee that they’re not bullying others and deleting those messages. However I’d hope other parents are monitoring their children’s phone usage and would tell either me or the school if my child was causing issues. That’s how a healthy community of parents are supposed to work.

Also your comment has a tone of “kids can find a way to bypass parental oversight so why bother parenting in the first place?” I don’t if that is intentional or not. But it’s an attitude I have seen other parents adopt and, unsurprisingly, their kids are usually the little shits that cause trouble because they know there are zero repercussions.