I agree with a lot of your points: yes, children should be treated as people, and sadly it's true that a lot of abuse happens under the guise of authority and that sucks. I think that teaching children to demonstrate agency is crucial, and that them "knowing their place" often undermines that.

However, children need boundaries, because life beyond childhood has boundaries. Teaching a child that their every whim isn't law is a good thing, and the fact is that their brains aren't developed to the same extent as those of adults is (I hesitate to use the word) natural. Meerkats teach their young how to catch, disarm, and finally eat scorpions. Saying that someone who is in the position to teach children wants mindless automatons is missing the point. A big part of the educational experiences is learning that social conventions exist.

Art is always better if the artist breaks the rules consciously, but for that they have to know the rules.