But for SO, where voting is never locked and content 'ages' at different rates, it's not so clear there's a downside. The "closed as duplicate" issue still stands, but rising user count is probably helping the problem.
The chosen answer was not the best, so my answer ended up reaching the top. But note that after 7 years, my answer, although still correct, is no longer the most efficient way to do things. Better alternatives are rising up.
I'm not sure what the deciding factor is now, perhaps there is a more complicated scoring system happening in the background or it recently changed?
If a better answer comes along in a question that is then marked as a repeat of a question that has a worse answer, forget it.
At any rate if a better answer comes along it should rise to the top in the matter of <24hrs.
And then the newest users can come and see based on the LATEST version which is the most upvoted answer.
The issue is that relevancy has a time-component, so there needs to be way to age scores as well to make sure the best answer for that time period is at the top.
Quora has recently introduced secondary voting mechanisms where answers will randomly have a "is it still relevant" toggle for users to continue providing signal beyond the initial vote.