Being open source by default doesn’t make a project secure and privacy friendly (especially if it’s server sided code. You can’t really verify for sure)
The VPN itself is secure, but it depends of an Google One account (not free). And respect of this, I found this in the FAQ page
Also, while VPN by Google One secures your device connection, it does not affect how Google collects data when you use our other products and services. For example, depending on your sync settings, Chrome will continue to store your Chrome browsing history to your Google Account. To manage the kinds of data saved to your account, you can review your Google Account’s privacy controls.
This mean, that my Screenshot isn’t a Joke, even if you use this VPN which certainly protect you from third party tracking, Google remain logging your data, because the VPN use it’s own Google servers with your Google One account, not free public servers, like other VPN. It’s a similar scam like the Opera “VPN”. Nice try, Google
If you want a good VPN, use Nord VPN, or if you want a good trustworthy free VPN, use Proton VPN free (no logs, no limits in amount of data nor speed, encrypted at military level, but limited to 23 servers in three countries and use in only one device (PC or Mobile) in the free version), Proton is also OpenSource.
At least, if you only need a VPN to protect your mobile in a public WiFi, Calyx VPN also maybe enough, it’s FOSS, encrypted, no logs, no account needed, no limits, but only one server from the Calyx institute, a non-profit education and research organization. Download from F-Droid.
