Speaking from experience, it's not only ID systems but if you run non-Android (some AOSP) they might still require you to install an App only available with Play Services or on iOS to do business with government agencies or even apply for funds in some European states. In other words if you are using GrapheneOS, from gov. agencies point of view you might as well be a criminal. Actually given how frequent ID-theft is nowadays, it's actually easier for criminals to launder their money than privacy preserving individuals or companies to pay taxes in EEA.