And for the record there is always a way to do all the listed things while being completely more or less naked (transparent clothing, frequent showerings, small discreet tatto, etc).
That said, I believe this is all irrelevant. Privacy is an end in itself, it doesn't need to be justified.
If you don't think governments can't change, I'd like to hear your opinions on how we went from a authoritarian (kingdoms) to democratic governments in the first place (or vice versa). Everything changes. Even societies change on micro (companies, clubs) to macro (governments or totality of the world) level all the time as new people arrive and old people leave.
US won't turn into Iran over night, it might take decades, centuries even to change into a totalitarian regime. But first sign is trampling your constitution. I'm not saying its going there but it could be going that way.