There are many fine RSS readers, but what I miss most was the social and community features.

The communities that spring up around things like GReader are like lightning in a bottle. Perhaps the companies that can afford to build things like that have concluded that other forms of social media are more profitable.

There still are niches of the internet that operate like a book club for excitable nerds, but they can be short-lived. Most eventually succumb to politics, lecturers, eternal September, and/or a zero-sum debate-team mentality.