The generic, ad-ridden wikis are everywhere, unfortunately, because the terrible service they provide is free. However, there are also lots of passionate people who pay to host their own MediaWiki servers, and then communities that populate it with accurate information! I think they deserve special applause for providing a really cool service that we mostly take for granted.

Some examples: https://bulbapedia.bulbagarden.net/wiki/Main_Page (Pokemon) https://minecraft.wiki/ (Minecraft) https://oldschool.runescape.wiki/ (Old School Runescape)

..only after I started putting together the list, did I realize that a lot of them are hosted by the same individual or community (https://meta.runescape.wiki/w/Weird_Gloop). Interesting!