There are some helpful posts here about using Graphene in the most private way (no SIM airplane mode etc) which are really helpful, and worth doing when possible.

But, as OP suggests, Graphene in general reduces your location info leakage. Sure, you wouldn't be safe from a targeted state attack, BUT you massively reduce the ease of which your data can be bulk analyzed by individual surveillance organizations.

Other OS also have the ability to turn off location, but it's not as obvious (there are so many exceptions when trying to do it in iOS). And using more private browsers with a VPN and clearing your browsing data will generally lower your footprint and make your device look more generic online.

The more people that do these basic steps, the better everyone's privacy becomes because it breaks the entity resolution methods used by big data firms.