Fantasy universes have always been a world that only lives because of its supporters. The Star Wars Extended Universe surely contributed to what the franchise is today. It seems that the owner of the brand decides what's canon and what's not, but where is the logic in that? If I throw money at Disney and decide that episode 4 features Jesus Christ, would that be considered the real story by the fans? Of course it wouldn’t. I understand that if you know what's canon and what's not, you know what to expect from a future official production, but if this changes so frequently all the time, who cares? So is there reason to specify what's “real” in a fictional universe?
The question was and is specific about SF&F. Is the canon obsession here healthy? Canon also sometimes doesn't explain things that content that got out of canon previously did. So would you answer non canonical or is it irrelevant to begin with? Also as stated in the comments, people often disagree on what's canon or not; you have to remember that there are stories where the creator/owner didn't bother to specify a canon. So, does it make sense to keep on discussing what's canon and what's not, and shouldn't there be a solution from SF&F? Something like a box you can check whether you care about canon or not canon. Also my question is about content that could reasonably be seen as canon (Like the Witcher games to the books), that doesn't include crappy written fanfic.