It’s like accidentally ending up in the background of someone’s photo at a public park versus someone actively following and taking photos of you.
In the past or in communities today where physical privacy is not always possible you will find there are a lot more accepted ways for people to separate themselves. Third spaces where you can be uninfluenced by the other party will be more common, going out for dinner alone or to the park alone are examples of activities that will be more normalized in those communities.
Your parents could probably be out the whole day without being tracked or recorded fully. However the modern day surveillance (including tracking of kids) means you will be tracked everywhere. You don't have the luxury anymore of going somewhere anonymous.
Ask your parents what they did when their sibling annoyed them.
Both of my parents grew up in very small houses with a lot of children, and my wife shared a room with her sister. I'd guess that the vast majority of humanity now, and certainly in the past, had very little individual privacy because there was no room!
It seems like a modern luxury in western suburban living. Nice if if you can get it, I suppose.