I think that smartphones with full keyboard and auto complete/autocorrect get you faster than 10wpm. Even the old number pad phones would beat that in the hands of your average 90s teenager.
I have a iPhone 13 Mini and generally just smash all over the place. I turned auto correct off and spell check on, because that seemed like the best method for me to just mash through my sentence and manually select the autocorrect/spell check option I want.
People could hit that speed on old numberpad based phones. On any decently modern smartphone with swipe IME enabled it's pretty trivial to hit 30-40 WPM.
Er, what? Without even trying hard I get (according to the typing.com 1 minute test) 58 wpm on my phone - and that's without using swiping or autocompletion.