They have been gathering data, identifying problems, making suggestions about solving problems, and everything that Congress has given them the authority to do. This is a larger country than Finland and the Netherlands, and a federation of diverse states, rather than a unitary government like those two.
If the Department of Education has not devised standards and imposed them, it is because the Congress has not authorized them to do this. Abolishing the Department of Ed. would make as much sense as shooting your dog for not fetching your slippers after punishing him for touching your slippers. NOT a solution.
We need MORE uniformity between the states, nor less. I have lived in Missouri, Kansas, Iowa, Washington State, Maryland, Virginia and Florida. Many Americans also move around a lot. We need national standards. Abolishing the Dept. of Education makes this much more difficult. It is a way of punishing the teachers for unionizing and voting for Democrats. It sucks.