Well you asked me about bullies and do I think we should control the actions of others, and you use the example of a bully in school. Of course your point is valid, as I think if someone is bullying your child we should absolutely control the behavior of that “other” child, the bully.
The point I am trying to make and asking you that question is this:
If you are trying to compare a child walking around without a mask as a danger to your child,
then you are saying that person should be masked. Which in turn means you think masks work.
but if you believe that masks work to help protect children, then why is masking your own child not sufficient? If they work who cares if the other child is not masked?
The vast majority of masks being worn by people, and an even higher percentage for children, are not N95. They are either surgical masks, or cloth ones.
There is no value to the wearer, no protection afforded them against the airborne virus, from using a surgical or cloth mask.
However, they certainly do work as spit-catchers. Both inbound and outbound. And although there hasn't been much study, I think it's reasonable to believe that there is some value in preventing people's spit from entering each other's mouths, either through coughing, sneezing, spitting, speaking, singing, or yelling.
So yes, there is some value in wearing the masks, for ALL people that will be within cough/sneeze/spit-projectile distance of one another.
That value is substantially less than vaccinations, orders of magnitude lower, which renders a mask irrelevant to people that are vaccinated. But for the unvaccinated which includes every child younger than 12, and a large percentage over 12, the masks provide at least some protection from being spit on by others, or spitting on others yourself.