All this babbling about complex constructs, it's really quite simple.

When we have no moments to outselves, when everything we know, we think, we do, is being recorded and processed (which it luckily isn't yet), then regurgitated in one way or the other, we lose identity.
Identity is a core part of being human. There are reasons that other people shouldn't know what we think, I think you can figure those out for yourselves.

So when someone says "They have nothing to hide", then they ignore a fundamental part of themselves, which they need to live. It's like saying someone doesn't need eyebrows, because they have no emotions to show. It is just false.

Everybody has something they do not want others to know. Whether it is you thinking badly about your elders, which you do out of love and to protect them, or thinking how your colleague is doing something wrong, which will train you to be better than them in that instance.

Once these things are no longer private, identities break down and society does not work anymore. Socialism, capitalism, communism, all those depend on faces.

This is even true for the animal kindom. Or do you think a lion could catch prey, if the prey knows the lion's thought, or the prey could escape the lion if the lion knew the prey's thoughts?

There are places where privacy can be instrumentalized, but that's where we can do something against it. The problem is about finding the fine line where we maximize privacy for a healthy society, while minimizing potential issues through it. We're way past that line.