They didn't get it "wrong". There's a million ways to do it, no matter what system you're using and none of them is zero effort. If you don't test your backups somewhat regularly, you don't have backups.
Your kids shouldn't need to worry about backups. Script them.
If you're scared of a cli and you're not willing to step out of your comfort zone, go for MacOS with Time Capsule, which is the only fully integrated solution that brings you zero involvement.