Most blog-entries were never much more than that anyway, especially since the free blog-services started appearing and setting up a blog was effortless. There is a reason why Twitter were named micro-blogging-service in the beginning. And the other side was blogging being a primitive form of social network, till better social networks appeared. So it made sense for people who were more interested in the social aspect to moved to the optimized services.
> I've been reading blogs and perusing my self-curated NetNewsWire RSS feeds for 20+ years, and blogs never went away, RSS never died, Google Reader getting googled didn't really matter, etc.
In both cases, the hype died down, and was replaced by other hypes. The remaining people use them now for the dedicated reasons where both can shine their best. But the danger remains that loosing support will long term lead to them dying for real. In case of RSS it's already happening slowly. Though blogs are more resistant to this, as your blogging does not depend much on external support, as long as you do not care about money or reader-stats.