I think an elephant in the room of this conversation is that if you came of age during the time you were playing some of these games we're talking about then there is no gaming experience that will ever compare to that. You only become an adult once, and growing as you're gaming, even growing while you're gaming, is an experience that keeps me coming back still. But to me you will never match the experience of the first time you really know what to do in an adventure game. The first time I realized in the original Legend of Zelda that I could just farm around for some Rupees, search out some heart containers, and get the white sword early was literally a powerful experience in my life. I realized that by doing something somewhat tedious I could get ahead of the game and then smash through four or five dungeons without much trouble. This is a transferable experience, and the place to now look for the mirror of that experience my not be found in gaming.
But as for the current state of gaming, I really do think that the most challenging thing for all of us right now is that there is so much of it and it's not being curated very well by those who are producing it. There are so many genres and sub-genres, graphical styles and playstyles, not to mention all the gimmicks clogging up the good gaming experiences such as day one DLC and microtransactions which were mentioned by others.
Games though, have always been a commercial enterprise. Now they're a very lucrative one, and a lot of people are getting in on it. Entertainment as a whole is shifting from large, single transactions to small transactions. Honestly I think Free to Play is a big problem in gaming, mostly because it's dishonest. It's actually "Free-to-play-to-a-point". And they don't tell you up front what point that is. I would prefer to take the risk and buy the game ahead of time.
Finally, I'd like to introduce another thought. This one's a question actually. I've gotten the feeling that certain genres and series' really do peak at a certain point, after which there's not much that company can do to build on or branch out on that gaming experience. For instance, I think Diablo 2 is simply preferable to Diablo 3 in every way. They simplified so many things in Diablo 3, from constant character respeccing to even the uniform size of items, such that the graphics upgrade is the only superior aspect in my opinion. Oh, and treasure goblins. Those are great.
I wonder if the same could be said for something like Final Fantasy 4 or 6 or Chrono Trigger as the pinnacle of 2D JRPG's. I wanted to bring up action platformers, but I think the thing that has supported so many of them is that you "are" that character, and so changing the character and backdrop amounts to changing the story you're reading from Fantasy (Mario) to Sci-fi (Blaster Master) to Cartoon (Looney Tunes), etc.
I know the "greatest" anything is opinion based, but regardless of your opinion on which one is the greatest, do you think a genre and theme actually objectively "peaks" at a certain point? I think this could answer some of the concerns of the original post as well.