de0u My understanding is that part of the point of Play Services, from Google's point of view, is that applications can offload some of their implementation to Play Services.
Yeah, that's what I figured was happening here. The problem is, if Play Services is not installed at all (as is the case for stock GrapheneOS), Google Maps will not tell you it needs it to function properly. If you install GMS but then disable it, Google Maps will tell you to enable it to use the app. This seems like an oversight on their part, since MS Teams will tell you it needs Google Play Services enabled to run, whether it's not installed at all or just disabled. Now, MS Teams doesn't actually need GMS at all if you only need the app to share your phone's screen during a meeting for one of your university class's final assignments, but that's beside the point.