Typically, this is because these questions are a minor (cosmetic or trivial) variation* of an question asked many times already, and usually addressed in the docs. Search results aren't likely to put this question at the top of results, so the aim is to resolve the OP's need.
*so technically not a duplicate.
The information overload then becomes huge. And I would like some more filtrering.
My approach today is to try to give quality answers when I can anyway. Even if the quality of the question is low. Sometimes I get surprised and the asker engages in a positive way. But mostly not.
I spend most of my time on Unix SO and it has a very low voting activoty bit a very high rate of "fix my problem".
So I try to be a good netizen but I feel more regulation is needed to fix the current status quo.
Maybe it's time SO adopted the concept of duplicate answers, not duplicate questions?
> Answers that do not fundamentally answer the question may be removed. This includes answers that are: > exact duplicates of other answers
However, this is left up to the community moderation rather than the diamond moderation. For the community moderation to delete an answer it must have a negative score and multiple 20k rep users have to see it and delete it. It takes a lot of work on Stack Overflow to muster that - especially when there are people up vote everything.
Consider https://stackoverflow.com/q/187587 and how many posts have the same content. Having experienced this in the past, flagging duplicate answers for deletion isn't something that diamond mods will act on... and as the answers have a positive score, the community can't act on without a concerted down vote brigade.