It's not the ephemeral stream that's the problem, it's the limited bandwidth.

You can show a lot more info on a screen than you can transmit through speech in a short period of time. That doesn't mean you read faster than you listen, just that sighted people essentially use their eyeballs as an "input device" to decide what information to look at.

If there's an object on the screen that you want to examine but that you don't need to click, you can just "navigate to it" with your eyeballs, without ever touching a mouse or keyboard. We don't have that luxury.

This means we need a much more efficient system for navigating what's on the screen, but that only gets you so far. Eventually, the easiest way to deal with this problem is just to increase the bandwidth of your channel, and you do that by increasing the speech rate.