Lithuanian there. I think we inherited a very similar system from soviet times.
Various things are slowly decoupled off the address registry. Major thing left is voting in election. Someone is eligible to vote for municipality. As in, for mayor of that municipality or it's parliament member. There're also optional municipality services that run off the same registry. For example, your kids may be rejected from municipality-sponsored kindergarten if you're not registered in the same municipality. This is to ensure another municipality is not receiving your taxes while you leech off neighbouring one. I guess that will get centralised sooner or later.
Various things are slowly decoupled off the address registry. Major thing left is voting in election. Someone is eligible to vote for municipality. As in, for mayor of that municipality or it's parliament member. There're also optional municipality services that run off the same registry. For example, your kids may be rejected from municipality-sponsored kindergarten if you're not registered in the same municipality. This is to ensure another municipality is not receiving your taxes while you leech off neighbouring one. I guess that will get centralised sooner or later.