I find voice-only conversations much less productive.

For example, over the phone, or over VC with the camera off.

With visuals, I can figure out what's resonating, what's not resonating, and adjust accordingly.

In a verbal-only communication channel, you get much less signal, and with a longer feedback loop.

If you're presenting something the other person might find controversial, you have to assume they are finding it controversial if they aren't giving you any verbal feedback.

That slows down the rate of knowledge transmission.

When you can read people's faces and know that they're with you so far, you can go faster through your argument.

This mirrors TCP's approach to retransmission in noisy channels.

When acknowledgments (ACKs) are missing or delayed, TCP assumes packet loss and throttles transmission rate, even if the packets actually arrived successfully.