How to use 'Hey, Siri' to control Google Assistant on iPhone
The best way to compare accuracy between Siri and Google Assistant is to use both on one device, and you can do that with your iPhone.
What is OK, Google?
“OK, Google” is the Google Assistant equivalent of “Hey, Siri”— you use it to activate the intelligent assistant in order to get answers to your queries.
The iOS version of Google Assistant was recently updated with the addition of support for Siri Shortcuts, which means you can now create a Siri Shortcut that lets you get help from the Assistant using Siri.