The dream of 1990s geeks have come true, I wonder if they're happy about it.
I think you have said the main reason:
Gaming has also become a lot more social over the years. Multiplayer is the norm and you can play with your friends 24/7 online.
Before gaming was for unsocial people, who can only talk about games in their occasional meetings... Now gaming is where most of the social interactions of young kids is.