There are a few different reasons why and how voice chat should be integrated. Listed below is just a few ideas on how integration should be added
1: Friend Voice chat.
You should be able to have people as friends and invite them to a voice channel party. There should be an open selection and a closed selection. The open selection would be that ANYONE on your friends list is able to join the “voice chat party” at any time. Then the closed “voice chat party” is invite only and you can only invite people through the friends list menu within lunar client.
2: Server Voice chat.
Within the server that you are on you are able to toggle on voice chat to talk to others. This would be a bit complicated with hypixel to disable during a game so that you can't talk to the enemy team. But, it should be enabled in public lobbies and have access. There should be a few options within the Server voice chat. Such as “Friend only” You will only be able to hear your lunar client friends that are in the lobby so there aren't as many players talking at once. This can also boost lunar+ sales due to the friend limit built within Lunar Client itself. Obviously this should be built into push to talk, etc.
3: Hypixel chat.
I am unsure how much hypixel gives Lunar access to their api so if there would be a way to include a voice chat for bedwars, skywars, build battle, duels, mega walls, and smp. If there were a way to quickly invite your teammates to a party with Lunar it would boost the average lunar player count on some Hypixel games.