For kids? Honestly, how do you know that? Literally almost no kid under 12 has died from Covid. That's a fact, so a Covid infection is certainly on the spectrum of LOW risk, particularly for kids.
Given that we don't know long term impacts of a vaccine that was literally brought to market in record time, I think the argument to wait on kids can be made very easily. Your point about Chicken Pox isn't ridiculous, but we know a lot more about that particular vaccine and it wasn't brought to market in less than a year.
There are studies on both sides, but kids seem to not be the major spreaders either.