You can enable Play Services and install them and use them, but why bother using a DeGoogled phone at that point? I use the OsmAnd~ (OpenStreetMap Android) navigation app, which navigates great, but it doesn't look up addresses very well. To look up addresses on Graphene I use an app called GMaps WV, which sandboxes the browser version of Google Maps, from which I can send the coordinates to OsmAnd~. That keeps Google from tracking my every move through the Google's Nav App.

Yes they do. I use a separate profile for Maps, and a different one for banking (I only ever need it to deposit checks, which I can't do on PC and I do all my other banking on PC) It's a pretty neat feature called Sandboxed Google Play Built into GrapheneOS, it lets you run Google apps (like banking apps or Google Maps) while keeping your phone’s strong privacy protections. Instead of giving Google Play Services full access to your phone, GrapheneOS runs it inside a regular app sandbox just like any other app, but with no permissions AND you don't have to be logged into Google AT ALL. In fact, it's an anon sign-in that's automatic. It never even asks you. Google Play Services only gets minimal system access it needs (like checking device integrity for banks). It's a walled-in scope this way, so it cannot see what other apps are doing, or see any of your personal data.