Graham Sutherland / Polynomial"texting a message used to take a time approximately proportional to the sum of the alphabetical indices of the message's characters modulo 3" is one of those things that is absolutely true but also 100% sounds like a shitpost if you weren't around for that era.
artemist@gsuberland gboard (google android keyboard) actually still supports a t9 pinyin input method for chinese. you need to select words out of a list anyway, so it's not too bad to make the input more fuzzy.
there's also a 5 button ime based on stroke, in that case the time used to type a word is related to how hard it is to write.