One thing that recently had me pondering was why do we need separate wikis, why not just add the information to Wikipedia? Unless your wiki has some feature Wikipedia doesn't support, it just seems to provide a background image and ads.
For example, I was looking up some Dragonball information, and their wiki was really sparse and didn't answer my question. So I randomly tried Wikipedia and it had all my answers
My only guess is some Wikipedia usage rules that say not to but I find that unlikely