Mine are 4 and 7
They need to be in school
But it was school that made the difference. As soon as should went back R was > than 1.0 and had been ever since.
And despite what some might say I don't believe for a second that the government understood the difference schools going back was going to make
I don't think that was just about schools though. A whole bunch of things happened in September. Colleges going back. People returning to offices. Gyms and (in most of the country) pubs and restaurants not only open but with must customers heading back indoors. Cinemas and theatres etc were operating. Other things were getting going again - places of worship, some face to face support groups, and parent/baby groups etc.
A lot of changes compared to the original closures that happened more or less at once - or that moved indoors, or gained popularity as people saw schools open etc and read it as "getting back to normal".
I don't think the government underestimated schools as such. They even said it would mean that something else might have to close (and then closed nothing)
I think they underestimated the weather and ignored just how difficult it is to keep bars, schools, workplaces simultaneously warm and well ventilated.
I think they also underestimated the message of "business as usual" that the schools and colleges etc reopening sends. Plus, if people rely on friends/family to pick up the kids after school then almost inevitably they'll start to sit and drinpk coffee together, or have a meal together or whatever - the fences come down and are hard to put back. Especially once the weather deteriorates.