What about servers that are built for people who are over 20 looking to improve? The one I run is for sharing personal art, music, crypto, nature, and talking about real life issues. It has some of the best people ive met from this board more attuned to old /r9k/.
Hating on the entire platform with how its presented on r9k is understandable tho.. its the newest trend of internet socialization and its dominated by degeneracy, but so is 4chan in general, at least with a server you can judge by character who is too edgy/young and who is chill/comfy enough to have an interesting conversation.
best of luck