TeamSpeak is basically what Discord replaced in many gaming communities/servers/groups. Before discord, most gaming groups would have a TeamSpeak, Ventrillo or Mumble server. These were self hosted (or hosted in a VPS) and generally worked better than Skype. TeamSpeak was the most polished, Ventrillo was kinda dated looking but worked well and Mumble was the free software that was getting started and is now pretty good