My guess is that It's going to improve the transparency and correctness of ideas. Every website will be like some sort of Reddit but more transparent because the publisher will not be able to censorship you. Also, cross identity. People will start having 1 public profile for every website. I can be Demi on hacker news, Reddit, Youtube, etc.
I like your thought except for having single identity. While its convenient, it could also be detrimental to the user. China is rolling out strict real name registration policies, for instance where you could become accountable for everything you say online.
It can be a good thing. Imagine Donald Trump saying that Obama wasn't born in USA. Obama or anyone could create an annotation with a witty response on that particular sentence or video time frame and a link to the PDF with his birth certificate. Trump could also defend himself inside the "fake news" by commenting directly and exposing the malicious attempt of manipulation.
