I don't think any of those were alternatives for gaming, which is what it was (still is?) marketed for.
If you wanted to play a game and do voice chat with a group of friends, TeamSpeak, Discord, and Mumble were the only options that were group-first (easier to do lobbies than single-person calls). Discord's UI is 2 decades ahead of Mumble / TS, and it's free.
If you wanted to play a game and do voice chat with a group of friends, TeamSpeak, Discord, and Mumble were the only options that were group-first (easier to do lobbies than single-person calls). Discord's UI is 2 decades ahead of Mumble / TS, and it's free.