I find your line of thought interesting but I’m not sure where you’re leading it.
And there are examples where this actually works - like the stock exchange: people agree that to be able to take good decisions, the publicly listed companies must be transparent.
Of course changing from "full secrecy mode" to "let's be more transparent" can't happen suddenly, but there are places where there are more transparent (ex: in Norway you can ask for someones tax declaration) and the country continues to function. And you can't do it in all places: if you are in a place where people hate each other for various reasons with passion (ex: skin color, place of birth, what you believe in etc.) then keeping secrecy is smart while the society solves the other things. If you think secrecy is what protect I think it is taking a huge chance. Hatefull people around will make at some point a mess and can affect someone, secrecy or not.
a) the rich and powerful would be able to use the secrets of the weak and poor to exploit and subjugate us even more
b) the rich and powerful would use their wealth and power to ensure that their secrets remained hidden, regardless of the law