You are positing that only questions with cosmetic or extraneous differences are marked as duplicates.
That's not the case. As a maintainer of a popular project who has engaged with thousands of Qs on SO related to that project, I've seen many Qs marked as duplicate where the actual answer would be different in a non-trivial manner. When I look at who all moderated on those Qs, they are usually users who haven't contributed to that topic at SO.
That's not the case. As a maintainer of a popular project who has engaged with thousands of Qs on SO related to that project, I've seen many Qs marked as duplicate where the actual answer would be different in a non-trivial manner. When I look at who all moderated on those Qs, they are usually users who haven't contributed to that topic at SO.