The local (German) government knows exactly where I live. My apartment doesn't have apartment numbers - as far as I can tell, this is common. Instead I live on the "second floor, right side" (2-R). This is what it says in my lease and on my registration with the local government, and, along with the street address, it uniquely identifies my apartment.
Besides, the very fact that one must register one's residential address with the government is contrary to the point you are trying to make. Even more bizarre, in my opinion, is the fact that I must also register my religion with the local government. (That is so that the government can collect "church tax.")
My experience living as a foreigner in Germany is that Germans trust the local government but not private companies.