In order to make it into a Discord or Zoom competitor you would need to solve far higher bandwidth things like HD video and low latency audio, and both of thouse are fundamentally very different things for a server to handle as compared to high latency short text messages.

Integrate into something that already exists, like Jitsi? Instead of trying to build one single app that handles everything, maybe it would be nice to have a suite of apps that all work together and can all use the same login.