How do we handle duplicate answers?

Question

I flagged a post for deletion that was (IMO) low quality being that it was more of a comment/question for more information than an answer. I had also posted onto the same question a duplicate answer that was (again IMO) higher quality as it actually answer the question instead of posing a question. However I posted after the initial answer (I can't remember what my reasoning behind it was).

In the flag I describe the situation as the flagged post was a more of a comment than an answer, and that the answer was clearer in my answer. The flag was declined with the following reason:

declined - this was posted before you even answered

While I don't really care about the declined flag, nor am I trying to get rid of a "competing" answer, I am more curious what to do about this type of situation where:

1. There are two answer identical in solution but different in quality
2. The newer question is of a higher quality than the original

What should we do in this type of situation?

Answer 1

The post could be easily rephrased as "check if the installation was successful". To me it's not really a question asking for information, but more of a question the author should ask themselves in order to arrive at the solution.

Also, the answer was posted before yours, so technically, if it weren't for quality reasons—and if we were a little more strict altogether—yours should have been deleted as a duplicate. (I'm not saying there's any reason to do so. Your answer is great.)

But more generally, if there are two duplicate answers, one lower quality than the other, simply downvote the other answer. Especially if these duplicated answers were posted within a short period of time (say, a few days), then there's no reason to delete anything.

Note that I'm talking about low technical quality, as in, maybe not explaining all the details or being wrong altogether. Those should not be handled by moderators. Low quality answers in the strict sense of being unsalvageable through edits are of course flaggable.

The only exception to all of this would be a rather low quality or mediocre answer posted to a question where practically the same answer has already existed for a longer time. By that, I mean months or even years. We often see people just scrolling past existing answers, posting their own solution, which then happens to be the same as a previous one. That, in my opinion, is worth deleting, and you can flag it for moderator attention using a custom flag.