Maybe gamers are getting older in general and realizing they don't have the time to dedicate to intensive games that are like taking on a 2nd job and studying for college.
I prefer games now where I can do the grindy stuff mainly AFK and do the challenging stuff solo in short bursts. No more 2-3 hr clan raids and shit like that anymore. Hell, sometimes I just start up MAME and set some classic arcade scroller to god mode because I just want to blow stuff up for a few minutes.