In my opinion there's a reason why people like to use platforms such as medium and it's exactly because they are more like "social networks".
Maybe you want to emphasize on shifting away from the "social selling index" and more on quality content. However, the type of persons that post this content already have minimal blogs on their own servers or someone else's (like Github pages or others).

So in sum, the people you are targeting already have their own platforms. You'll need to offer something extra, maybe linking the platforms that already exist together (Something with RSS).
That's one thing I've noticed over the forums years, most will prefer posting on their own blogs instead of posting on the forums if there's no incentive to post on the forums other than discussion. What you post on something you own links back to you which is not something that isn't always existent on platforms that don't fall within the super heavy social kinds like facebook/medium/dev.to/etc.. Maybe an ability to easily export the content you've created with the comments to it would make a change.

If you want we can continue brainstorming more opinions in this thread about what could possibly be done. I'm also open to ideas for changes on nixers and link with other communities.