You do get used to it.

You can still run Google Maps. Install the Play Services via the Graphine App Store then you can install the Play Store, then you can install Google Maps.

Or you can side load Aurora Store and download G'Maps from it (still probably need Play Services).

Using the Play Store or Aurora Store should allow you to install apps like normal. I personally haven't run into any "it won't run on GrapheneOS" issues.