Kids of wealthy families with parents with flexible jobs will be fine. Not every kid is in a home situation like that.
Like if isolating that kid doesn't prevent any further infections, then it isn't doing any good. If isolating them for 3 days prevents a couple other kids from getting infected, it's less clear.
Using PCR tests to evaluate clearance doesn't make sense though, since they can be positive if there are fragments but no viable virus.
It's a cost and time issue. The cost of filtering snot, inoculating a culture dish of infectable cells with the filtered snot, waiting a couple of days for the cells to show signs of infection (cell swelling or bursting), and then running a PCR test on the cells in the culture dish. With high enough throughput you could probably do this for $50 or there about, and maybe three days, to verify whether they were technically still infected three days ago.
Just waiting a couple days after symptoms abate is also going to bring most of the benefit of testing for clearance.
The weekends do count, out of the 10 days they'd be out, up to 4 would be weekend days. So, really they'd have missed around 6 or 7 days of actual school. But it could also happen to fall in a public holiday, which will reduce the number of days even more. And there are school breaks throughout the year.
I find it hard to believe that many people are living such in the edge that, if their kid has to miss a week or so of school in a year their finance and jobs fully crumble.
I think you're vastly underestimating how often kids exhibit symptoms potentially consistent with Covid during a school year.
This was always true, and we never sent an obviously poorly child to daycare/preschool/school.
I've lost count of the number of times I've picked up one of our kids from daycare/preschool/school before Covid after a phone call along the lines of "your child has spiked a fever/vomited/has had an accident and should probably see a doctor".
Wasn't this typically based on common sense by the parties involved, though?
Catch C19, recover, get the sniffles in the next 2 months, get PCR tested, require a parent to take off work and the kid to sit out 10 days [possibly more than once] is not a reasonable policy IMO.
Which is why the EU issued the "recovery certificate" and put it on the same basis as a negative test, and why our schools didn't test recovered children (to clarify: were mandated not to test recovered children) after they returned to school after having Covid.
Is there any evidence this is different for Covid-19 than the vast sea of other viruses kids catch but we don’t PCR test for?
The kids around the world ended up having to take nearly two years off of school and it was shown to have a massive effect on their development.