I don't play OSRS, but my partner does, and on more than one occasion they've shown me a page from the wiki and I've felt the exact emotion you're describing. Even a lot of enterprise software tools struggle to produce docs as good as the OSRS wiki's.
Probably related that it pertains to a game built on a 2000 engine. The lack of complexity and repetitiveness is built into the game, which directly correlates to the popularity among the autism community.
