At least some people (e.g. me) can type faster on a decent QUERTY keyboard than they can speak. Dylan might be one of those people.

Then there's editing what might start out as dictation. I've seen Dragon used for this; it's awkward and slow. I setup a PC for Harry Stubbs (who wrote as Hal Clement - the 'Barlenan' stories and more) so he could double-check orbital mechanics. I saw his process a little bit - and there was a lot of editing involved.

That said, I can speak a lot faster than I can use a touch keyboard. I'm so painfully slow my wife laughs at me. But there's speech-to-text on mobile devices. On Android, it's on either the Google keyboard and the SwiftKey keyboard, probably more (hey, it's android, everything's an app, including keyboard and launcher). I imagine it's available on iOS as well.