You keep using the term “secure” that it sounds like you think education is like a prison sentence. You’re not doing this for security but for safety. A stair gate or drawer child-proofing lock are by no means secure but you use them anyway for the child’s safety.
You can’t just leave every dangerous thing out in the open because you “view it as a pain to deal with” storing them safely and then blame everyone else for the situation that follows.
Our realities might be different but in my reality if you put 0 (zero) effort to keep some critical things safely away from your child because it’s too much of a hassle to do it, or they’ll get around that anyway, etc. then you’re failing your children.
You make it sound like having a phone in public is basically "open carry" which is absolute nonsense.
What do you have on your phone that's dangerous? Phones aren't safety device, and they shouldn't be turned into one.