Great post, Dylan. I think Medium has proven that the desire to write thoughtful, lengthier forms of content is alive and well. This platform, much more so than Facebook, Twitter or even Tumblr, is the logical evolution of the self-publishing tools of the early Web 2.0 days. So all is not lost :-)
That said, I think the idea of a fully open and interoperable social toolset as described by Berners-Lee is a good one, but probably doomed to fail. People crave simplicity and ease-of-use above all. It’s why Apple has always succeeded and it’s why Facebook continues to succeed. Unless Solid can reduce the friction involved in social sharing even further (hard to imagine given Facebook’s ubiquity) I don’t think concerns around content ownership or profile-based marketing will be enough to convince people to move. Ello tried to get people to move to its platform with many of the same lures. As far as I can see, it hasn’t worked.
As someone who’s been working on the web since ’97, I sympathize with the nostalgia one can feel for the “good ol days,” but judging purely based on the world’s enthusiasm for today’s tools, I suspect we may be engaging in the equivalent of mourning the loss of stick-shift transmissions in the age of electric cars.