let me list two not federated options.

but both are self hosted.

• lobsters. one active instance is lobste.rs but i know of https://սարեան.ցանցառներ.հայ

• if you use gemini protocol, you probably know about it: bubble is a reddit like software. i know about two deployments, the original, by the author is at gemini://bbs.geminispace.org

users also can have their blog feeds on it.