This post got really long... Games in the last year that gave me "that feel" I used to get, where I want to just play and play nonstop included:
* Stardew Valley
* The Witness
* Ratchet and Clank Remaster
* Enter the Gungeon
* The Witcher 3
* Fallout 4 (this one actually had some pretty mixed reception though)
* Cities: Skylines
* Mario Maker
Some games I'm looking forward to are Uncharted 4 (today), DOOM, The Last Guardian, No Man's Sky, Deus Ex, Final Fantasy 15, ReCore, Scalebound, Pokemon Sun/Moon and of course Yooka-Laylee. and maybe Sea of Thieves grumble grumble
As you can see, there's a huge range of genre, so it kind of depends on what you're into, but I feel those titles are all worth examining. I don't think games are any worse than they ever were, despite all my favorite titles being N64 or PS2 titles.
To address "What Changed"... I think having to "find yourself" as a gamer has many factors, and many relate to age and time.
First, it's a factor of time. Now that I'm an adult I get maybe 6-10 hours to play per week. Some weeks I get lucky and can squeeze in a 40 hour gaming week, but it's not the norm. In high school however, there was a summer I played WoW 14 hours per day. I slept 7am to 2pm that summer. I did WoW basically the rest of the time. Aside from that insane outlier, I certainly averaged 5 hours of gaming per day from middle school all the way up until college graduation. I could dedicate time to getting 100% in games, I could dedicate time to exploring every corner of a game and trying to figure out how to get into secret doors in Banjo Kazooie that don't even open in reality. Now, I play a game and I usually have an hour or two to "make progress". I recently finished Ratchet and Clank, and LOVED it, but am well aware I will probably not be getting 100% because I have other games to move onto. Now I mostly beat a game's story, and move onto the next, with some noteable exceptions (Stardew Valley most recently).
An additional factor, as an adult I have more agency to buy games. This seems good but causes problems. If I want a game, I don't have to ask my parents. I just get it. When I was very young I would get maybe 1 game per month, or every other. As a result I really had to squeeze every drop out of a game. Now I have a Steam Backlog of over 300 games I've never even installed. This leads to a problem where that you become overwhelmed and never make a choice at all. When I go on steam, I have some 400 games, but I usually open the same few... which I've already beaten.
In terms of "games getting worse" or "concepts being over-milked", I think this is because you now have so many games to compare every release to. When you got your first game, it was the best game you ever owned. When you had ten games, you probably had three favorites. When you have 100 games, a lot of them start to look similar. This is only slightly the developer's problem. There are only so many ways to build a wheel for example. Platformers have to have platforms and jumping. Shooters need shooting and Adventure games need environments to explore. These aren't really wheels you can adjust that much and eventually the hundreth platformer is going to be a little derivative. Now there are thousands upon thousands of games in existence. It really becomes difficult to truly stand out. And thanks to nostalgia, your favorite games will probably be older anyway. My top 5 games are STILL Banjo Kazooie, Paper Mario TTYD, Banjo Tooie, Paper Mario 64, and Ratchet and Clank Up Your Arsenal. Some genres are of course more guilty of being derivative than others (Call of Duty, NFL/NBA/Baseball games, etc) but I think there are only so many iterations on a theme that would even work.
And lastly... yeah, gaming has changed. Most games don't have codes in them anymore, achievements are everywhere, social aspects (Facebook-ing of online gaming) have been shoehorned in, DLC is now available and put to varying degrees of effective use, microtransactions can now exist, etc. Heck, the internet exists now so things like the "Mew hidden under the truck in Pokemon Red" are no longer even a thing. The internet will figure out all the secrets of a game in a week, if not in mere hours. Crowdsourcing the rumor mill is both great and terrible. The entire environment has definitely shifted, but I don't think it's a bad thing. Some games have done DLC really well, achievements can be fun if done well, the absence of codes is a little disappointing but besides that it all seems to come down to execution. Just like there are hundreds of old, AWFUL platformers nobody remembers, there are currently tons of examples of DLC done wrong. And that's just because it's current. Someday we won't remember those examples just like we don't remember... I dunno, some terrible platformer.
Make the forum great again.