OSM does not rely on imports that much, many cities have fantastic geocoding potential because local mappers poured their sweat and local knowledge into it. ;)
I think you'll find that without a data import, address data tends to be forgotten by many mappers. Compare Chicago, which did have a bulk data import, with San Francisco, which did not. In Chicago, every house number and building is mapped, but in SF you'd have to interpolate the numbers.