I feel like you only read half my comment each time.

You will always reach a point of diminishing marginal returns with measures taken, and you have to evaluate the impact of the measure against it's effectiveness.

The argument is that school closures likely did not contribute sufficiently to justify their extent of implementation, meaning you probably would have wanted a few more people dying to avoid the shortfalls in children's education and socialisation that you have now. The ends, in retrospective, arguably did not justify the means.