We don’t know an infinite number of things. You can’t make decisions based on unknowns. You have to make decision based of evidence, not the lack of evidence.
What? Of course you can. We know there's potential long term health effects in adults who get COVID-19, there's risk children face the same ones. We don't know how severe or how likely children are to get them (much like in adults), but we can absolutely decide not to take the risk anyway, and keep kids out of schools.
That way you cut down tremendously on a potential vector of transmission with as limited an impact as possible. We've done this here in NL successfully and in other countries besides.
Certainly many people make all kinds of decision based on irrational fear.
“We know there’s potential long term health effects” — without a percentage qualifier of how many people are affected, and a qualifier on the magnitude of the effect, this statement is utterly meaningless. There’s “potential long term health effects” (of some unspoken magnitude, to some unspoken percentage of the population) to everything.
“We don’t know how severe or how likely children”.... hundreds of thousands of children have tested positive for COVID. What we know for sure is that most will never know they ever even had it, and of those that do, less than 1% require hospitalization. 10-24 year olds are about 25x more likely to die of suicide than of COVID. (6,500 vs 175)
One thing we absolutely do know for sure is that social isolation will increase the suicide and overdose number in older kids. We also know that detected cases of children abuse and neglect are way down since lockdowns started, and it’s not because kids are being abused or neglected less. We know many kids primary source of good nutrition comes from school lunches. The evidence all points to closing schools being more dangerous for children than opening them. Particularly for children in low income households.
There may be an argument for closing schools, but it’s one that sacrifices children‘s social, mental, and economic wellbeing for the sake of potentially lower transmission among other truly at-risk populations.