What is your opinion on state openness and public scrutiny?

Since I've joined Lemmy, I've been trying to learn more about leftist political systems and how current activists would like to implement them. I'm also interested in building a nuanced opinion on historical implementations of Marxism.

In my understanding, public scrutiny can be multiple. About methods: free press, direct reports from the state, NGO or foreign observers; and about subjects: military, internal or external affairs, industrial.

What effect does state transparency have on society (good or bad), and would you prefer to live in an open political system personally? Which kind of transparency?

During the cold war, how open and transparent were the USA and USSR? How open are the US, China, Russia and the EU currently?

Do you know resources that approach these subjects that I could read?