Lil heads up for google one users with a pixel 7* & pixel 7 pro*
As of December 2022, Pixel 7* and Pixel 7 Pro* consumers can access VPN by Google One at no extra cost on those devices through the Google One app without a Google One subscription
If you have one of they devices install the google one app to benefit
Thats if you wanna trust a VPN service by google
So far i can't find anything to suggest google are using another VPN service to use for their VPN
all other google one users need to subscribe to the 2TB deal to get the VPN as an extra
google claim
Our client libraries are open sourced, and our end-to-end systems have been independently audited.
source code >> https://github.com/google/vpn-libraries
independant audit >> https://research.nccgroup.com/2021/04/08/public-report-vpn-by-google-one-technical-security-privacy-assessment/
more here
6 question's you might have about VPN by Google
https://blog.google/products/google-one/common-questions-vpn-google-one/
Once you install the google one app tap on the VPN option that you see and then the URL "learn more about VPN by google"
There you'll find all info