These two apps are not comparable. My guess is that 90%+ of people using Discord are doing so for the low-latency voice conversations with optional screen/game

These two apps are not comparable. My guess is that 90%+ of people using Discord are doing so for the low-latency voice conversations with optional screen/game sharing. Zulip does not have first-party voice chat. You would be more likely to get gamers to switch to a Teamspeak server.