I would bet it’s more like “gaming has expanded to a larger market”. Gamers who were willing to fiddle with computers and online gaming, hell, up till the late 2000s are probably also the same type of people who are willing to be patient and fiddle with a complex game and learn where the fun is. Now playing a game is easy as 1,2,3 no matter where you get it, I’m not talking down on anyone, and I don’t care if that’s where the AAA trend is going, just that when the access gets easier the group expands to more and more casual audiences.
Also, console games have always been way more “casual” as those markets expand gamers kind of defacto have a larger preference for casual games.