"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.
There have been other studies that have found effectiveness, and basically all agree on no downside.
https://www.mayoclinic.org/diseases-conditions/coronavirus/i...
As far as children, there are a lot more negative effects that can happen that aren't fatal. There is a lot we don't know still