I think a lot of us grew up with siblings in the same room. Rooms didn’t lock. Parents not looking but knowing all too well what’s going on. Schools reporting on behavior by phone or by letter that as a kid you didn’t get to see.
I think for me the notion of ‘privacy’ was just being left alone with no one bothering me. It’s only as an adult that I have a clear perimeter where no one should be able to step in. In that regard having a lot of your doings leaked to parents might not be that impacting.