True privacy isn't hiding something from everyone; it does mean being able to share something with only the people you choose to share with.
For example, when we send an email, we are be pretty confident it only goes to the people we select and not the entire Internet. The vast majority of emails are only read by its intended audience. That's privacy.
I agree with you in general. E-mail has a little more structural security though, there are never world-wide glitches where everyone can access other people's private photos mailed years ago. (Think of the imgur dump of Zuck's private photos.)
For example, when we send an email, we are be pretty confident it only goes to the people we select and not the entire Internet. The vast majority of emails are only read by its intended audience. That's privacy.