Comment by Nathan Arthur (nathan-arthur) on A Wiki for Questions · 2021-05-11T23:30:29.647Z · LW · GW

You may also be interested in the StackOverflow Documentation project (now defunct). I think it attempted to do something closer to what you're suggesting.

Comment by Nathan Arthur (nathan-arthur) on A Wiki for Questions · 2021-05-11T21:18:39.534Z · LW · GW

StackExchange only flags duplicates, that's true, but the reason is so that search is more efficient, not less. The duplicate serves as a signpost pointing to the canonical question.

Also, StackExchange does indeed allow edits to answers by people other than the original poster. Those with less than a certain amount of reputation can only propose an edit and someone else has to approve it, and those who have a higher level of reputation can edit any answer and have the edit immediately go into effect.