It would seem beneficial to add a different kind of challenge, where the challenge is accompanied by an alternative full POI data. Successful challenge would not just wipe out the POI, but would replace it with the proposed alternative location, title, description and other metadata.
The rationale: sometimes there is a challenge pointing out some inaccuracy in the POI, but voters cannot be sure whether the challenged POI will be replaced by a better version. Since imperfect POI is often better than no POI at all, it’s often unclear how to vote. “Challenge with proposed changes” should enable more incremental improvements to the map, without losing POIs unnecessarily.