Are tasks like responding to emails and adding comments limited by typing speed ? I would have guessed most typing tasks aside from copying text are limited by knowing what to type.
Pretty much all of the time I'm typing natural language (chat apps, emails, writing this comment here) I'm going to be limited more by my typing speed (~120WPM) than by the speed at which I can think of the words I want to type.
A pretty trivial demonstration of this is that I can talk much faster than I can type, and I would expect that you can too.
I can talk much faster than I can type, but I have much higher standards for precision and language quality when writing. When I write in natural language, I almost always carefully read through my message once or twice before sending. I don’t think doubling my typing speed (currently around 80 wpm, I guess) would save much time.
I think it's frequently the case that you determine what you're going to type in a block-wise fashion. You know roughly what the next paragraph/sentence should look like, and then "speak" through your typing. If you type faster, you will almost certainly "speak" faster in this way.
