This hodge-podge of facts strung together without any compelling analysis feels blind to history at best, highly misleading at worst.
It is a sadly Western view, ignoring the East, that overlooks thousands of years of global history. What appears to be happening is a hypothesis that privacy is short-lived in history is taken and then tried to be proven by example. For some reason you are ignoring all the facts that actually disprove your theory, let alone discussing them and explaining them away.
For example, “most homes didn’t have separating walls until invention of the chimney” is so obviously wrong on multiple levels.
First, a small “home” wasn’t in history the same place as we assume it to be today. Having a private moment could mean leveraging the huge abundance of naturally formed private areas in nature (e.g. waterfalls and snow block voices from carrying). Your analysis of private space is completely backwards. Even the fact parents have sex in front of children means sex is considered less taboo because lack of stupid taboos about sex, not that the parents value privacy less.
Second, the chimney dates back to around 10,000BCE. To argue rooms are tied to chimneys is weird on this fact alone. But more to the point I personally have walked through various separate rooms of a palace, including rooms with private bathing, built around 35BCE that had no chimneys.