In a manner yes. you are correct. Accounts could possibly fix this. There would still, however, need to be an administrator to put the specific content app content on the device and physically monitor the child in some way. You could limit say internet by locking a setting with a specified user name (child) and duration, etc. so I do see the point it would make it "easier" in this instance. At least you could be in the other room instead of hoovering over the child to see what they are actually doing every instance. And I agree 100% with your last statement lol, simply look to what happened in LA when the kids bypassed all the school security packages to use the iPad's as THEY saw fit lol.
Maybe an option for you, although (to be fair to me here lol

) this is off the hip so I haven't committed much real thought to it, is this: what about using privacy lock settings. In this manner you can turn off wifi/cell signal and turn off certain apps. Then the setting will not allow changes to be made to those apps or those settings until a password is entered. So using the Internet, the child could be in the other room but if you have the app turned off and they try to turn it on they will be prompted for the password. Then you do that for all of the apps and just monitor time of use for the child. Just an idea.
Have a great day.
USVet96