Okay I just had a HUGE idea but I do not know enough about RSS to implement it - I am so willing to learn but a couple weeks isn't enough time!! So if there's anyone who has the time and skills, please consider this proposal!
Here's my vision: coGhost, a system built on RSS the same way pesterchum is built on IRC.
coGhost feeds would have additional data besides the standard RSS data: images to use as profile icons, formatting data for shared posts, that kind of thing
coGhost clients (the original client would be FOSS to make it easier for people to make their own) would display posts based on the formatting data (with the original client being styled like the cohost website), automatically update the user's own outgoing feed with both original and shared posts, and of course give the option to share posts from another feed (with or without additional commentary) while correctly attributing the source and giving you the ability to click to follow those source feeds.
There would obviously be no tags, search, notifications, or comments section. I think that's actually in the spirit of cohost anyway! For discovery, people could set up directories on their personal websites. No numbers, only connection!
Nothing would be stopping someone from using a regular RSS reader for coGhost feeds or a coGhost client for regular RSS feeds other than the formatting looking a bit weird.
Please please let me know if you'd be interested in rushing to work on something like this - it wouldn't have to be perfect when cohost goes read only, just functional enough to use!
Also please let me know if there's more tags I should add for visibility!