Both iOS and Android contain settings that allow the user to disable Google Maps using mobile data and still allow all other online functions of the smartphone to function correctly.
You do need to download the offline map for the area you want to navigate in before turning off Mobile Data.
On iPhone, go to Settings/Google Maps and turn off Mobile Data.
Android instructions are from Bard.
"Set Google Maps to only use Wi-Fi
This will prevent Google Maps from using data altogether, unless you’re connected to a Wi-Fi network.
Open the Google Maps app on your Android device.
Tap your profile picture or initial in the top right corner.
In ATG 1996, a caller asked how they could set up their daughters’ navigation so it does not reroute. No real solution was presented. It was also discussed that turning off one’s smartphone’s mobile data would work, but would also stop all online features, such as streaming music. Then, during ATG 1997, that call was discussed again, and still no real solution other than to use an actual GPS device that does not use real time traffic condition updates. So, I presented what I thought might be a valid solution that still allows for other online features to continue working.