I just wanna say I like the idea and I think you're (OP) right on the mark on there being people who prefer communicating by voice in an informal setting instead of using text. Voice may be, in certain situations, a higher bandwidth medium since intonation may be incorporated. On the flipside, I personally feel like I could be exposing more of myself to the world than I'd wish to with voice.. like people with particularly unique voices may fear de-anonymization via voice.

Overall, I think it's a project worth playing around with, and who knows, traction could start building up.