We are fairly certain that the real-world use of cloth masks and face coverings can only supply limited benefit, so the threshold for harm to make them not worth it may not be that high [0]. You can support wearing masks for adults in motor vehicle agencies (limited harm, limited benefit) and still realize that young children in daycare should not be required to be masked all day (potentially high developmental harm, limited benefit).

"In summary, though we support mask wearing by the general public, we continue to conclude that cloth masks and face coverings are likely to have limited impact on lowering COVID-19 transmission, because they have minimal ability to prevent the emission of small particles, offer limited personal protection with respect to small particle inhalation, and should not be recommended as a replacement for physical distancing or reducing time in enclosed spaces with many potentially infectious people."

[0] https://www.cidrap.umn.edu/news-perspective/2020/04/commenta...

My original comment suggested simply that the claim that wearing masks around children would harm them requires evidence. But the comment I was responding to here made the claim that the harm caused by masking in front of children is unknowable. I submit that if a harm is truly unknowable then we may as well treat it as no harm, since in this case common sense tells us that children are adaptable and resilient. But please, if you have a reasonable estimation, do share.