Just to be clear, the problem here isn’t entering text, but with editing it. With better keyboards, voice transcription, and physical keyboards on many tablets, getting text into a device is not the problem it used to be. However, you will always want to edit your words afterwards.
I personally don’t like speech-to-text because then you’re broadcasting every word you write to everyone around you.
It might be better with a specially-trained model that uses stenographer-style compression that only you know, so drive-by eavesdroppers can’t translate your text entry on the fly.