You can still use Google Maps without an account and "incognito". I wish they'd allow app store usage without an account though- similar to how any Linux package manager works.
That's not really the issue. The issue is that for google maps to work properly, it requires that the Play services are installed. Play services are a massive semi-monolithic blob that requires tight integration with Google's backend, and deep, system-level permissions to operate correctly.
In addition to F-Droid, you can get Aurora Store (which is on F-Droid) which lets you use an anonymous login to get at the Play Store. I use it for a couple free software apps that aren't on F-Droid for some reason.
