I know I'm only one person, but this idea that covid is running rampant in schools just doesn't tally with what I'm seeing day to day. I'm in one of the worst hit parts of the country, and if the rate of cases identified in schools was the same as it is in the local community then my secondary would currently be seeing about five kids test positive every day, and a member of staff every 2-3 days. If schools were actively driving infection then you would expect it to be even higher. Instead we've had four pupils and two staff test positive in the entire time since we've been back, and at least two of them were already self-isolating because a household member had it, so they more than likely caught it outside school.
I don't think my school is doing anything special in terms of preventative measures either, as normal colds are rife - I've been off twice to get tested in the last month, both times negative - and, frankly, I can see that not much distancing is happening, despite their best efforts. I don't know of any schools nearby that have closed completely, which isn't to say there aren't any, but I would definitely have heard if it was happening all over the place, and again you'd be expecting to see multiple kids in each secondary school test positive every day given the community infection rates. If that was happening we'd surely see mass closures pretty quickly, however much the schools tried to keep it under wraps.
I can think of three reasons why positive cases might be lower in schools than the local area in general: first, families might be being more careful than adults without school-aged children if they're worried about disruption to their children's education; second, children could be more likely to be asymptomatic and therefore cases aren't being picked up; and/or third, it might actually be true that children don't spread it as easily. I don't think the first one can be solely responsible, as there are hundreds or thousands of families in most schools, and they're not all going to be that conscientious. Unfortunately we can't easily distinguish between the last two without mass testing of both school communities and random people across the region, and given that the testing system is struggling to accommodate even those people with symptoms, I'm not sure we have the resources to do that currently.
I would fully support measures to mitigate potential infection rates in schools, if nothing else because it would also reduce the massive disruption that's currently being caused by everyone being off with normal coughs all the time, but equally they have to be proportionate. There's no point spending huge amounts to create extra space or having kids in on a rota (or not at all) if it turns out that schools aren't actually a significant factor in transmission. So far I'm not totally convinced that they are, but whether that's just because the data hasn't been collected/published, it's hard to say