Don't be ridiculous. COVID-19 was never a serious risk to children. It's less dangerous to them than RSV which has been around forever, and we never forced people to wear masks because of RSV. And there is no reliable evidence that masks were even effective anyway.
"The high risk of bias in the trials, variation in outcome measurement, and relatively low adherence with the interventions during the studies hampers drawing firm conclusions."
There have been other studies that have found effectiveness, and basically all agree on no downside.
I think it's pretty clear that we didn't (and still don't) understand either the disease or the consequences of the actions taken in response to the disease very well.
We didn’t even understand the mitigations that were enacted, which is the worst part. To this day nobody can provide evidence that the lockdowns or almost three years of mask mandates did a single damn thing. And if the answer requires a phd to understand, it means it was never worth doing because the massive easy to foresee collateral damage would have outweighed whatever minuscule benefit the measures had.
I've downvoted you because COVID, while less likely to harm children than adults with comorbidities, was still a danger. I know because I had to take my 9-month old son to the hospital twice when he caught COVID. He developed a fever over 104 degrees both times, threw up anything more substantial than water, and barely responded to anything because he was exhausted but unable to sleep with the discomfort.
I know it's anecdotal, but I can't help but get upset when people say it was "harmless" for children (not your word, but one I've heard often).
https://doi.org/10.1002/14651858.CD006207.pub6