Why on earth do you think high reading level is a skill that correlates with the ability to parse legislation? I've literally had somebody trained in law try to explain specific laws to me and be completely wrong. Knowing long words isn't going to help you. A similar argument applies for your other examples.

If you think that reading level is just "long words" then your literature teachers completely failed you, and I'm sorry.

If you're reading a technical document aimed at professionals in the field, I literally don't care what your reading level is: you're not going to correctly parse the text unless you have the background knowledge the text assumes you have.

If you have a high enough reading level you can do further research to learn what the experts know. You can read multiple sources and make your own connections. You don't have to trust someone just because they say they have expert knowledge - you can check them.

If you're reading an article aimed at a general audience, then congratulations: it's already written in a way that you can understand it, because it's aimed at a general audience. If nobody could read it, nobody would buy it.

So if most people can only read at a 2nd grade level it's okay for journalists to write articles like See Dog Run? How are we supposed to communicate complicated ideas without complex language?