https://www.macrumors.com/2018/07/25/siri-on-ios-latest-test/
Google Assistant answered 85.5 % … correctly and understood all of them, Siri answered 78.5 % correctly and misunderstood 11. Alexa correctly answered 61.4 % and misunderstood 13, while Cortana correctly answered 52.4 % and misunderstood 19.