All of this is work, more work, admin work, things I would pay an assistant to do. Why would I want to be a system administrator when I can just not give my children systems that I need to administer?

This type of solution provides a simple system that requires very little administration and supervision. The problem with modern communications tech as it relates to children is that by default these systems provide access to every adult on planet earth to your child's inbox. That is not a feature that I need, but rather is a crippling design flaw much more likely to harm my kids than it is to help them.