I think you have the causation exactly backwards - the vain culture is what gave rise to social media. Japanese "social media" including forums and image boards

I think you have the causation exactly backwards - the vain culture is what gave rise to social media. Japanese "social media" including forums and image boards are biased towards being nonentity as possible. Famous cat owners make efforts to be non-entity as possible compared to US ones often involving owner presence even if just dangling a toy and talking to the cat. Japan sure as hell isn't perfect socially but they demonstrate that the source of social problems may be found in the mirror collectively and not in new technology.