As qznc started, those are separate things. One is a crazy leftover from Napoleonic days (consider the amount of changes to German statehood that thing has survived!), the other is an opt-out thing (or rather an opt-in actually, unless your parents did the "in" for you) that I actually think is super nice to have. It should be extended to the point where it's basically an API for income-scaled membership fees that's open to every org that wants to have it (and to public broadcasting, to achieve "separate from state" in a way that isn't a flat household tax)