How would opening up Facebook change the internet?

If believe that if there was demand for an "open Facebook", there would be an "open Facebook". And I say this as a HUGE fan of all things decentralized, open, and federated. I want the return of UseNet, WAIS, Gopher, RSS, etc., and widespread adoption of Atom, AtomPub, ActivityStrea.ms, APML, Salmon, WebFinger, blah, blah, yada, yada etc. But in reality, consumers have had chances to adopt these things and they have (mostly) chosen not to.

The optimist in me wants to believe that with sufficient "market education" people could be induced to desire an Open Web that includes open social networking, but frankly the evidence available to date doesn't support this belief. I mean, Mastodon / GnuSocial are available today, so why aren't most people switching?

Perhaps if a Facebook alternative emerged that was clearly better in enough ways to be compelling in and of itself, without needing the user to care about federation and decentralization, it could get somewhere and just introduce those things as a side effect. But, again, people have tried and thrown lots of money at this. Google (with G+), Ello, and others[1] have tried to establish a FB alternative with real traction and have mostly not succeeded.

[1]: https://www.fastcompany.com/40559106/the-privacy-first-socia...