I think people have very different approaches to social media, and of course there is no one size fits all. But you provided some good for thought.
I navigate the social landscape in a very different way than you have described; I use LinkedIn purely for business and professional purposes, Twitter as an extension of LinkedIn, Facebook purely for connecting with close friends and family, and Steemit for blogging and content curation with an emphasis on creative writing. I don’t want to suggest that I present myself as a different person on each platform, but my purposes are very different. For example, I don’t imagine sharing my Steemit content on LinkedIn; I guess I feel like that would be like trying to sell fiction to a high tech trade magazine. But if all aspects of your life are aligned, it would work very well.
Totally agree with you, all social media platforms and people are different. I act totally different on snapchat than on steemit. Snapchat is more fun and raw. I see your perspective :)
I do sort of wish they all connected up somehow, though. All those platforms and methodologies are a lot to manage!