Missed me by that much!

Ah, like the Cone of Silence from “Get Smart!”

Speaking from experience from the last five years, it’s been pretty good for me.

Nextcloud has chat capabilities. Perhaps it might be overkill for chat alone but presumably you also want some collaboration with documents.

Budibase.

Hashtags are your friend. It also helps if you have some active posters for the tag. I get good content from following #sciencefiction #coffee and #python.