> Is there any proof that actual people use and value Google and Amazon assistant more than Siri?
I found at least one measurement report: As of July 2017 Verto Analytics showed Siri on top[1] with 41.4M unique users per month (but falling), and Alexa with only 2.6M (but rising fast).
[1] https://techcrunch.com/2017/07/11/siri-usage-and-engagement-...