That would imply there was online privacy at some point, or at least that it was a thing that all users could reasonably understand and achieve.
If users understood that Facebook's business model might eventually require what (in hind-sight) appeared to be multiple privacy violations, but continued to use the service anyway because they couldn't help themselves, they really never had online privacy when using the service.
For those of you down-voting me, I'm pointing out this is a fallacious argument talking about online privacy. The companies who built these huge platforms didn't bake in online privacy when they built and evolved their systems. Talking about it like we've "lost it" is pointless, but I do think it's worth exploring how we can make it better!