Well, this already fails for places that don't address by street. You might think it's only some pre-industrial villages in the jungle, but examples would be some eastern European countries and Japan - some (but not all) buildings simply don't have a street address. Instead they have a number within a district. But sometimes it's a building number on a street, but it's distinct from the street's numbering system, so you can have Building 5 on st. Foo as a distinct address from 5th Foo st., where there is a completely different building. And of course there's no number on Foo st. that corresponds to Building 5. Another fun case is when there's a district Foo and a street Foo and e.g. Google Maps resolves "district Foo, building 5" as "No. 5, Foo st.". Or when the district has a number in it, so "district Foo 3, building 275" resolves to "district Foo, building 3", because of course the first Foo doesn't have a number in it - there's no Foo 1, only Foo, Foo 2, etc.
Generally all residential buildings built by the communist regime follow that system, while older buildings follow street numbers. Open Street Map actually deals amazingly well with our addresses, while Google Maps fails miserably most of the time. This is starting to become a problem as online services here are integrating google's mapping technology, e.g. an app for hailing taxis would ask you to type in your starting and destination address and if google can't make sense of it, the taxi can go to some completely wrong place. I can deal with it fine since I live here, but woe be any foreigner that would rely on Google Maps.
The postal system works just fine, but sometimes I have to enter a district name in the street field in online forms. As long as it arrives to the right country, the postal workers here can make sense of the address just fine.
All of these shenanigans do work in a hierarchical way, so you can pretty much expect to always have City, City sub-unit, Building designator as your address schema, but the actual category of City sub-unit and Building designator is sometimes "Street/number", sometimes "District/building number". You can of course simply ignore that and not have your system work in weird places, but if you're making a library for wide use and publishing it, I would appreciate it if you take into account that not everybody addresses by street/number.