Blizzard Voice Chat, introduced in late 2016, is a voice chat system built into the Battle.
As good as any 3rd party can go, it can never beat in game voice because not everyone will be in the same server able to hear you.
Almost every modern game has an in game voice client that allows players to communicate, there's no reason for WoW to have an archaic system when it comes to communication.
Remember, you don't need a mike to be in Blizz voice comms, you can just listen in.
A Ready Check sends an "Are you ready? It's not bad if you want to just talk in game real quick without needing to get on discord.
I would also recommend doing a full Just keep in mind it will wipe your addons.