Voice control wouldbe a huge QOL feature, especially for inventory management.
QOL for hands
You could say "equip bow" and your bow would be equipped from anywhere in you inventory or "equip netherite blocks" to grab netherite blocks, even if they aren't in you inventory.
Villager interaction
You could greet villagers with "Hey you!" to start a trade.
You could trade with a villager, say "trade 23 beetroot", Or "trade 56 emeralds for fortune 3 book".
Saying "This is all garbage", "I hate wandering traders!", or "Gooday, villager" could end your trade
Quick crafting
You could say "craft wooden pick" and it would click the wood pick recipe or "craft wooden pick 24" to click 24 times.
"Craft all available wooden pick" would shift click the wooden pick recipe.
Social interaction
Have a voice recognition for talking into chat (probably with google speech to text for more accuracy), "open chat", then "Hi everyone, I'm a completely normal person" then a pause and "send" would post "Hi everyone, I'm a completely normal person" to chat.
Other baked phrases such as "hello everybody" could be triggered by saying "post in chat hello everybody" for not sending your voice to google.
Inventory Management and Hand Crafting
For inventory management, each slot could have a letter and number, so you could say "split a5" (right click a5) then "craft 3" for the 3rd crafting slot, then "select coal 24" to click on wherever the coal is 24 times then "craft 1" to place it in the top left crafting place.
"craft everything" would then shift click the result slot.
Some other notable commands: "Transfer to" transfers held object into another container, "Transfer a1 to" Transfers the first inventory slot to another inventory like a chest, "transfer row a" and "transfer column 1" do as expected "transfer everything" is inv dump, "equip a1" attempts to equip as if armor, "unequip 1" removes helmet, "select arm 1" would click on the helmet.
Hot is hotbar instead of a letter
1st, 2nd, and 3rd row could be used instead of A, B, and C for potentially better accuracy
Some reference
Microsoft Speech Recognition or Voice2Json could parse the voice commands, see https://github.com/YihaoPeng/DragonbornSpeaksNaturally/ for examples on how it was done for Skyrim
Microsoft Speech Recognition (built into windows) or Voice2Json (a bit harder to setup, but with much better accuracy) can be told which phrases to listen for, and doing that makes them very reliable - they will never get something like "salad ate for" instead of "select a4". Saying "That salad ain't for me" might be recognized as "select a4", but the sensitivity is adjustable.
But Why? This Would Be Really Hard To Do.
This would totally revamp the way Vivecraft is played, making it as simple to use as a keyboard and mouse. It would remove the roadblock that makes Vivecraft difficult to use, GUI navigation. PvP would be a lot more accessible if saying "hot 1" equips your bow, saying "hot 3 offhand" equips your trident to your offhand, and saying "equipt golden apples" would be as easy or easier then opening the inventory and putting them in your hotbar. It would also make building, crafting, smelting, chesting and chatting with friend a whole lot easier. In my opinion, it would be worth the effort.
Customization
Then there is the customization. Everything could be customized, set a mod's hotkey to o and make "fire in the hole" activate your mech's super laser instead of never using it. "Do a dance" could activate an emote, "I need health" could equip your splash potion of instant health II, "HELP ME" could put "/t teammate Help me! I'm at 1441 15 -18772!" into chat. You can customize everything for each world or modpack or server you play with, without having to worry about not using your gigantoraptor because you don't have enough buttons on your controller or not being able to compete in Bedwars because it takes to long to buy things and to chat with teammates.
Voice Control in VR
Voice control wouldbe a huge QOL feature, especially for inventory management.
QOL for hands
You could say "equip bow" and your bow would be equipped from anywhere in you inventory or "equip netherite blocks" to grab netherite blocks, even if they aren't in you inventory.
Villager interaction
You could greet villagers with "Hey you!" to start a trade. You could trade with a villager, say "trade 23 beetroot", Or "trade 56 emeralds for fortune 3 book". Saying "This is all garbage", "I hate wandering traders!", or "Gooday, villager" could end your trade
Quick crafting
You could say "craft wooden pick" and it would click the wood pick recipe or "craft wooden pick 24" to click 24 times. "Craft all available wooden pick" would shift click the wooden pick recipe.
Social interaction
Have a voice recognition for talking into chat (probably with google speech to text for more accuracy), "open chat", then "Hi everyone, I'm a completely normal person" then a pause and "send" would post "Hi everyone, I'm a completely normal person" to chat. Other baked phrases such as "hello everybody" could be triggered by saying "post in chat hello everybody" for not sending your voice to google.
Inventory Management and Hand Crafting
For inventory management, each slot could have a letter and number, so you could say "split a5" (right click a5) then "craft 3" for the 3rd crafting slot, then "select coal 24" to click on wherever the coal is 24 times then "craft 1" to place it in the top left crafting place. "craft everything" would then shift click the result slot.
Some other notable commands: "Transfer to" transfers held object into another container, "Transfer a1 to" Transfers the first inventory slot to another inventory like a chest, "transfer row a" and "transfer column 1" do as expected "transfer everything" is inv dump, "equip a1" attempts to equip as if armor, "unequip 1" removes helmet, "select arm 1" would click on the helmet.
Hot is hotbar instead of a letter
1st, 2nd, and 3rd row could be used instead of A, B, and C for potentially better accuracy
Some reference
Microsoft Speech Recognition or Voice2Json could parse the voice commands, see https://github.com/YihaoPeng/DragonbornSpeaksNaturally/ for examples on how it was done for Skyrim Microsoft Speech Recognition (built into windows) or Voice2Json (a bit harder to setup, but with much better accuracy) can be told which phrases to listen for, and doing that makes them very reliable - they will never get something like "salad ate for" instead of "select a4". Saying "That salad ain't for me" might be recognized as "select a4", but the sensitivity is adjustable.
But Why? This Would Be Really Hard To Do.
This would totally revamp the way Vivecraft is played, making it as simple to use as a keyboard and mouse. It would remove the roadblock that makes Vivecraft difficult to use, GUI navigation. PvP would be a lot more accessible if saying "hot 1" equips your bow, saying "hot 3 offhand" equips your trident to your offhand, and saying "equipt golden apples" would be as easy or easier then opening the inventory and putting them in your hotbar. It would also make building, crafting, smelting, chesting and chatting with friend a whole lot easier. In my opinion, it would be worth the effort.
Customization
Then there is the customization. Everything could be customized, set a mod's hotkey to o and make "fire in the hole" activate your mech's super laser instead of never using it. "Do a dance" could activate an emote, "I need health" could equip your splash potion of instant health II, "HELP ME" could put "/t teammate Help me! I'm at 1441 15 -18772!" into chat. You can customize everything for each world or modpack or server you play with, without having to worry about not using your gigantoraptor because you don't have enough buttons on your controller or not being able to compete in Bedwars because it takes to long to buy things and to chat with teammates.