Thumbs up for Apple distinguishing themselves by their pro-privacy stance, as opposed to MS, who don't have anything to win by Win10's excessive "telemetry" IMHO.
I recently realised that any company taking on Google (e.g. Apple, Mozilla, ...) that is afraid they won't be able to take them on in areas like machine learning or sheer size, is realising, rightfully so, that being pro-privacy is the one thing they can compete on with Google that Google will never be able to imitate. Pretty sweet, actually.
That being said, and I've never used Cortana or Alexa, but I hear they're pretty decent compared to Siri.