Ready Player One is all about fandom elitism - you’re not a true gamer unless you know all sorts of ridiculous trivia and have nostalgia for these very specific approved pop-culture elements (even if you are wildly distorting them and forgetting the things that made you love them, looking at you Iron Giant). You aren’t a True Gamer unless its audience decides you are.
Wreck-It Ralph 2, OTOH, is literally told through the eyes of people who have zero concept of online or gaming culture at all. It specifically highlights the sort of casual games that RP1′s fanbase loathes, and portrays them as fun and entertaining. (For that matter, so did the original.) It celebrates that geeky culture is becoming more widespread and accessible, rather than bemoaning it.