Not only does it need voice chat, I believe a distance-based vc would greatly enhance the experience, as in only being able to hear the people close to you, with doors and walls muffling sound and so on, it would just be SO much better
I believe it would add depth to the experience instead, just like being actually next to the person, the crew has new ways to verify intention, the impostor has new ways to lie and enter the safe zone of all the rest, a whole range of possibilities could open, hearing conversations through walls, being able to hear the people near you even if in the dark, a talk with the impostor before being killed, etc.
What if you could hear murder?
That's the idea.
Then that'd completely ruin the game, you're not supposed to hear a murder through a wall. It'd do nothing but make the game super easy and annoying. VC should only be for the meetings and nothing else; hell the game even tells you to "shhhhh" before gameplay starts so it's designed around not being able to communicate until the meetings.