Yep. Use MatterMost self-hosted at worst, or something simple like OpenFire/XMPP
If anyone can recommend any other open platforms for me and the other concerned readers of this post, that would be highly appreciated.
In my mind, federation is a pretty important feature, as it allows you the possibility to bridge the gap between all the disparate chat systems we currently have. Chat bifurcation is a major issue that is serving to help divide us all.
Personally availability was always a major issue to me when it came to older self hosted solutions, with Discord I don't have to worry if group B has someone willing to bother hosting because it's always there hosted on Discord's servers and if something happened we don't suddenly lose our hub and chat.