It is really nothing particular about schools. In Spain the first day schools were closed children started playing on the streets, or playing basketball and soccer(you can play soccer anywhere). They were quite happy doing that.

Then the authorities said: No, no no! Kids must stay in house all day, closed all public spaces, something contranature for kids.

It was the get "in house", secluded, don't do anything socially. Too many don'ts with no does.

I can stay indoors playing guitar or piano. Reading books,or HN, or cooking. Even then I need to get out from time to time. It is not realistic to expect children doing the same.

Most of those activities were not really dangerous with some restrictions.

You can go in a bus or car with mask if people don't talk and introduce air from the outside.

You can play different basketball or football games with little risk. You can jump rope. But bureaucrats decided they were little monks. They are not.

School is not the necessary thing here. It is playing socially and exercising what children need like water and air.