Except that every new question gets shut down as a duplicate and the older question being "duplicated" is 5 years old, full of obsolete answers, doesn't address the subtle differences in what people are asking, etc.
They want to use the Q&A format to build something Wikipedia-like for each site's subject areas but the incentive structure hasn't lead to Wikipedia-level content curation.
Mailing lists, sub-Reddits, forums... they all end up high duplicative. But people are also paying attention to all those duplicated answers, and the next go 'round they contribute an even better answer, and maybe that ends up in a FAQ or wiki and someone actually puts in the effort to keep it up-to-date.
Or Google figures out the best answer based on being newest, click rates, whatever other voodoo that they do. Which, in my experience, is almost never a Stack Exchange.
