It could use GPS for rough geolocation, and 3D models of all the scenery could be generated. New contribution traces would contain changes compared to the past. Volunteers could request new paths it would like to see explored, and OSM could propose paths that cut through or ride along segments of recently submitted recordings of other users, to check if those changes are real, without checking the whole suspected recording.
Separate ground truth recording from its interpretation into mappable concepts, going out to make a recording or observation is a different task from deciding how to canonicalize the content.