I asked a question and discovered after some time that it is a duplicate. I flagged it (my question) as such but my vote was recorded as a vote only.
Why isn't it authoritative to close the question as duplicate?
This has been asked a few times on Meta.SE as it applies to all of Stack Exchange.
That one has been a feature request since July 2015, and various folks agree it would be useful, but there is no action on it yet. From looking at those type of questions it looks like it's not high enough priority to get it done "now", as the existing functionality does work as normal.