As I work on #1099439275348602990, I think I'm closing in on the "right" structure for Yakread to take as a reading app. I plan to limit the scope to reading for a while as I focus on growing the app. But in the end game, IMO it does make sense for the core social media functions--reading, publishing, discussion--to be bundled into a single app. The key is that those functions should still be interchangeable. e.g. you can read blog posts in the same app that you use to publish your own blog posts, but (1) you can still read blog posts that people publish with different apps, and (2) other people don't have to use the same reading app as you in order to read your blog posts.
This way you get the fully integrated social media experience by default, which is important for mass adoption, but you aren't stuck there. Power users with different needs can switch out parts of the app for 3rd-party implementations, and the ecosystem as a whole can be more gradually adaptive instead of lurching from one VC-funded behemoth to the next.
(Aside: this does have some slippery slope issues, because even if your all-in-one social media app does work with external content, as your userbase grows, the temptation to favor in-network content--e.g. by boosting it in the recommendation algorithm--will always be there. That'd be another benefit of #1100165507509911705. It would be great if there was at least one neutral, open-source social media app of this kind.)