I don't disagree that it feels like things have slowed down, but I certainly wouldn't say that nothing's moved forward in the past 3 years.
We had the Tomb Raider reboot and AC IV come out both of which I felt had progressed in some way, the former modernizing a franchise (it had its flaws but I thought Lara was a well done female protagonist which is still rare) and the latter introducing piratey goodness and great naval combat. Yes, AC has regressed somewhat since then, but it took 4 AC games from AC II for them to switch up the formula; AAA is a slow moving beast which is unfortunate.
Then we had Wolfenstein: The New Order which was a very pleasant surprise. I also enjoyed D4, but that's probably because I'm one of the crazy few that still enjoy playing Kinect games and I much preferred playing that ridiculousness without a controller.
Shadow of Mordor was mentioned and then there was Murdered: Soul Suspect (really awkward title) which had a lot of issues but also some interesting ideas.
Then we had Alien: Isolation which feels like a legitimate horror game for once! Arkham Knight tried to innovate - and failed miserably, but still tried nonetheless.
Sunset Overdrive felt like a refreshing change of pace from all the games that have been taking themselves way too seriously. They may have gone a bit too far off the opposite end with that one and some of the humour fell flat, but it had solid and interesting gameplay that felt like a nice fusion of THPS and Ratchet & Clank.
Watch_Dogs for all its hype and disappointment also had some interesting ideas that had they been more fleshed out and substantial would have made that game much more interesting. I played it a year later after all the hype had died out and I had almost no expectations which also let me appreciate the new things they'd tried to do. I imagine letting a player control an open world indirectly whilst also being able to interact with it as a player character was not the easiest to implement (and, of course, it was an Ubisoft game so it had to have towers/outposts/click-here-to-reveal-map-thingamajigs and countless pointless collectables).
Then there was Fantasia - I know, another Kinect game, but quite possibly my favourite music rhythm game in the last few years. Sure, it's a niche game, but one that also introduced a new type of music rhythm game.
I'd even argue that Halo 5 is probably the one that has changed up gameplay the most for that franchise. It doesn't exactly introduce anything that hasn't been done yet, but the gameplay was really enjoyable (except for those warden fights when playing solo). It also suffers from a story that barely progresses for the duration of 15 missions and a lot of characters are barely fleshed out let alone have an actual arc. So maybe it's a regression on some fronts, but oh well, can't win em all!
Lastly, I'm not trying to claim that all the games I listed were actually any good, just that they all tried to innovate in some way (whether they succeeded or not doesn't matter) and were all developed by fairly large, generally AAA teams (except maybe D4 and Fantasia). I haven't mentioned any Sony exclusives as I haven't really played any lately and thus can't say much about them. Is this 2 pages yet?