The power of a service like this is slotting in your own alternatives to the underlying services. Like supermarkets building their own brands around bestsellers. You could wean people out of walled gardens. "What's the Mallary alternative to this?"
"When FriendFeed was active (2007–2015), major social networks provided open, unrestricted APIs that made aggregated timeline streaming straightforward. Modern platforms like X (Twitter), Instagram, and Reddit have locked down their APIs."
https://share.gemini.google/wsPvn2L4gZK1
Reverse the trend. "Use open standards but compete on implementation" ... from the old Sun Micro playbook.
See Surf:
"Combine people and posts from Bluesky, Mastodon, Threads, Flipboard, YouTube, and more to build custom feeds for your interests. Add a hashtag and others can join your feed!" https://surf.social/