Needs significant UI polish IMO. Anyone from the Zulip team care to chime in if there's appetite for this? I could take a look at contributing if so. Just the project getting to this level of maturity without significant polish sort of triggers the "maybe maintained by people who just don't value it that much" alarms?

It already is!

(EDIT: unless your reason for using Discord is PTT voice channels. Then it's not.)