>would be immensely useful in countless ways for the management of our society,
Such as?
Now, maybe if one person had an IQ of 80 and the other contender had an IQ of 105 it seems like it could be useful in some particular fields. But for the most part you'll run into the "I'm 200 times smarter than you because my IQ is 102 and yours is 101".
And there is no icing on the cake. Privacy is a multipolar topic and there are many pros and cons around it.
We have rights not because they are some intrinsic part of the universe, or inalienable text written by a deity, we have rights because people working together and learning from the past mistakes in history have decided that something better than what was is attainable, and the moment we forget it something worse will take its place.