The issue with RSS is it is tied to the "long form" blog model* where a post requires a subject line. Most RSS readers do not do a great job displaying posts wi

The issue with RSS is it is tied to the "long form" blog model* where a post requires a subject line. Most RSS readers do not do a great job displaying posts with no title. They also don't typically do anything with inline hash tags (inside the body content). With Facebook/Twitter/Etc (short form content) there's a very informal text box. Hash tags get processed inline with the body. It makes posting something incredibly low friction. A blog post that will actually show up correctly in an RSS reader has much higher friction. Boosting a blog post (reTweet or equivalent) is also high friction. Blogging never went away and blog hosts exist but "Social Media" style short form content exploded because it's low formality and low friction. Other features like direct messaging or posting picture and video are done online in the apps. A lot of early effort with that sort of stuff on blogs died early because it requires not just support in the blogging engine, but moderation/administration done by the owner of the blog and support inside the RSS software. * long form might only be a sentence