Your thought experiment exists in a utopia where the above isn’t the case, which isn’t really applicable to any human society that’s ever existed. The top of the food chain will Until humans stop forming hierarchies, we need rights.
Also the "every human society that's ever existed" isn't true, because for sure when humans were nomads, you basically knew what's happening with everybody in your tribe, transparency was at 100%, privacy at 0. It's also the case today in many places such as small villages where everybody knows what everybody else is doing and it seems to be ok.
My point is that no matter what society you look at, the privileged get the nice things (like privacy) automatically whereas the underprivileged have to get it encoded into law, and even then it's not guaranteed. It's a rigged game, and the right to privacy levels the playing field.
When humans were nomads, we didn't have human rights so the point is kind of moot, but we still had secrets (even if gossip made it harder to keep them secret) and we still had a strong social hierarchy with privileged elders.
If transparency is the norm, governments need to go first.
Since that will never happen, the only solution remains privacy for all, or no government at all.
people need privacy because others' intentions and judgment are unworthy
if you've ever known anyone who was gay, who got divorced, who secretly had a deprecated ethnic background, who left their faith, who didn't want their ex-boyfriend to know where they lived, who revealed government corruption, who struggled for political change, or who could be raped or robbed by a stranger, you've known someone who needed privacy
even though they had nothing to be ashamed of
you might argue that if nobody had privacy, nobody would be able to get away with rape, or with lynching people they discovered had a drop of black blood, or with lynching apostates, or with gay-bashing, so these things wouldn't happen in a world without privacy
that would be a stupid argument because people did those things openly all the time, and they usually got away with it, and some of them still do; humans have a social pecking order, and it is defined by aggression with impunity
also people murder their ex-partners all the time even when they won't get away with it
this is poorly expressed, but i think you're trying to say that privacy can only be justified to hide 'unwanted' things, and so, for example, arguing that people need privacy to hide being gay implicitly accepts that it is bad to be gay; is that what you meant?
this is the premise i explicitly rejected in my comment; to use that example, this is an instance of what i said
gay people need privacy not because being gay is bad
gay people need privacy because others' intentions and judgment toward gay people are bad
you seem to be arguing that it would be good to improve others' intentions and judgment toward gay people, and this is correct, but there are limits to how much mere exposure can effect such a change
i am not willing to sacrifice gay people's lives for that
it should be extremely obvious that your reasoning is invalid in some of my examples
your teenaged neighbor doesn't want everyone to see her in the shower and to know when she's alone and unprotected because she's vulnerable to being raped
there is no assumption that the shape of her breasts or her walking home alone last thursday are 'something different and unwanted' or in any way bad; quite the contrary, her ability to walk home alone is precisely the good that it is important to protect in this situation
the problem is, as ought to be obvious, certain other people's intentions toward her; she needs privacy to protect herself
I understand what you're saying but my point is if we didn't try to protect X, it would eventually be normalized, become part of daily life and not noticeable as a thing that needs to be protected AND that it seems that when putting protections for X, that protection implicitly includes the assumption that X is bad. A naked body isn't inherently an invitation for rape, unless you implant that idea into someone's mind through the ban of public nakedness, and being gay isn't a thing to judge, unless you make it a taboo and discourage its public expression.
I'm not convinced, the real life evidence in actual tolerant societies seem to suggest that the more open we are, the less secrets we keep and the more transparent we are, life improves.
Because we have structured society and our culture in such a way that some people can only feel safe when inside a small thick wall cell with the door locked behind them. That's terrible though, my proposition is to invert that, what would allow people to sing in the streets without any fear of judgement, and use that as a basis. Privacy as an idea suggests "let's put more doors with locks" when in fact that doesn't help at all. It doesn't address the problem that necessitates those doors with locks to exist.
Separately, privacy and secrecy are related but distinct things. Telling me that you sing in the shower is a different thing than inviting me in to see and hear it.