I wouldn't mind seeing a two-tier approach, with authoritative municipal data as a base (see https://openaddresses.io/ https://openaddresses.io/ for an example

I wouldn't mind seeing a two-tier approach, with authoritative municipal data as a base (see https://openaddresses.io/ https://openaddresses.io/ for an example of collecting a large number of sources and normalizing it) with user-submitted edits on top.