Wanted to capture this here as this letter to Mark Zuckerberg is so spot on - particularly this paragraph:
I believe that future social platforms will behave more like infrastructure, and less like media companies. I believe that a number of smaller, interoperable social platforms with a clear, sustainable business models will usurp you. These future companies will be valued at a small fraction of what Facebook and Twitter currently are. I think that is OK. Platforms are judged by the value generated by their ecosystem, not by the value the platforms directly capture.