The thing that help you navigate inside buildings is called "Network Location".

Google and Apple provide this functionality by collecting Wi-Fi and Bluetooth network data from all their users and creating a massive database.

By default, "Network Location" is disabled in GrapheneOS. If you have Google Play Services installed, you can use Google's Network Location service by enabling those options.

Fortunately, GrapheneOS provides an alternative using Apple's network location services. There is an option to use GrapheneOS proxy server instead of connecting directly to Apple. Of course, whether you use this feature should entirely depend on how much you trust GrapheneOS developers. This one works using just Wi-Fi data and I use it daily.

I can't tell you if you should or not. I can tell you I DO NOT have it enabled and mapping service work just fine. Also I would recommend using something like CoMaps and not Google Maps.

Remember when phones had that insane super advanced tech that could guide anyone anywhere, even offline?

Seriously, why doesn't the compass exist anymore?

I have never turned on location anything on grapheme.

On my other phone I have also uninstalled google location services/history, WiFi scanning, Bluetooth unknown tracker, etc.

If I get lost in a building... I ask someone.