> People you like would have signed profiles that tell you where they publish so that you can subscribe. You can follow their interest graph but use your own algorithm to filter and rank content.

Solving custody and permissions issues in a scalable way hasn't really been doable here, not in a way that isn't massively out-performed by The Platforms. I believe the semantic web makes sense for this, but people have demonstrated that privacy, and positive vs negative externalities concerning data, aren't as important as core functionality.

Another thing to consider is that content is fairly commodity compared to being apart of the reaction to that content. Configuring your own web to allow for this is a lot more work - the Facebooks curate this for you, as a matter of engagement.

I love your comment though, this is where my thoughts have been for a while now. If people could serve, or have served, their own interest graph and activity, that would be the basis for a lot of interesting things, including qualifying organic activity, and real sentiment.