From How should duplicate questions be handled?
When are two questions considered duplicates?
According to Stack Exchange co-founder Joel Spolsky, we should only close real duplicates, and according to co-founder Jeff Atwood, there are three kinds of duplicates: cut-and-pastes, accidental duplicates, and borderline duplicates (requiring judgement as applied ...
This is sorta not supposed to happen
And saying that sounds weird, because it obviously has.
But let's work though how things supposed to work.
A question asks about the solution to problem X. Answer give the solution to X and why they're correct.† As long as that is happening, any question asking whether a specific answer is correct would be a dupe because ...