Why? It hasn't even produced results. Every country that has closed schools has seen a standard increase in infections at the same rate as countries with kids in schools. As kids who aren't in school are outside, using the public services that are caked in germs, or gathering in malls and McDonalds' and other public places en masse.
Schools can control the cleanliness of the interior of their buildings, they can sanitize, they can check temperatures and they can most importantly know exactly where all the kids are. Not to mention it can prolong the amount of time the economy can continue to function at a normal rate as people continue to work.
Kicking everyone out at home is only theoretically helpful, people still need to go buy food, or important supplies. Shoving people into their apartments/homes middle of the month when money is waning and saying "we'll fine you if you come out" is just a panic button response and likely a waste of time and public resources.