I used to play EVE Online a fair bit, and always thought it interesting how some of the groups used Discord but only for text communications. Voice was still done over Teamspeak or Mumble.
When I played EVE, Mumble was the de facto voice comms since it supported 100s of pilots which happened many times during joint ops and xmpp for text chat and pings.
AFAIK most of the gamers choose it for voice chat (Anyone remember TeamSpeak?)