How about
Q: Where can I find an arse-tonne of information about Unreal Engine, Unreal Engine Games and modding for Unreal?
A: At BeyondUnreal or one of their extensive wikis.
It's free so what can possibly be wrong with the idea?
There's a small enough number of people who put time and effort into maintaining the existing repositories, and they don't have or don't want to spend additional time maintaining a duplicate resource when it would be more efficient to redirect people to the resources which already exist.
Sites like stack overflow et al work extremely well as Q/A sites but there's just so many of them now that search engine results for many topics just come back with pages of results of people asking a question in myriad different ways and getting answers to that specific question. This
doesn't help people find information on the wider topic, because the site is a Q/A site not a general repository covering that subject. Even if the site in question
does make some effort to group related questions, the information it can provide is still constrained by the general Q/A structure and the universe of questions it has answers to.
Essentially, once a Q/A site has one question on a subject, it needs a whole slew of other questions to make it a useful resource - in all other cases it's merely polluting the search results. Worse still, these kind of sites get relentlessly mirrored and duplicated by awful spiders like bigresource, which further pollute the search results to the point that
actual useful websites are relegated to spots on page 2 or 3.
So the response at the start of this post might seem a little tongue-in-cheek, but if you really want to help people find information on unreal-related topics, and you are unable to realistically guarantee that you can provide
all the information contained herein in Q/A format to allay the point I made above (which in the real world you won't be), then it's the most useful thing you could do.
As far as longevity goes, I think the argument is moot as well really, since with a few notable exceptions, no site is beyond the chance of being shut down. Surely it's better to pour resource into the sites which do exist, in the hope that they'll become better and last longer, than it is to meaninglessly and uselessly thin out the concentrated wisdom that exists in the extant repositories.
tl;dr version: Q/A sites are killing the internet, big up beyondunreal instead so search engines return it first