I still feel the pinnacle was ~2011 Windows Phone. It was some kind of swipe-to-type, but maybe not Swype specifically? At any rate, it seemed to use "how humans actually talk" as a guideline, because it was do a great job of predicting what words I would actually mean to use in a row.
Modern keyboards are like, I know you just said "I want" but instead of predicting "to" I predict "rip". I mean the letters are close. And "I want rip" makes way more sense than "I want to." You're welcome!
The fact that Apple will as often as not autocorrect grammar from actually-correct to wrong -- and systematically screw up spelling -- in not just transcribed Siri but also in typing is just inexcusable at this point. It will even Randomly capitalize Certain words!