2017 and 2019 were great years. 2021 will likely be great too, a lot of delays and good games on the radar. The only let-downs are the retarded console stuff, but at least we won't see a new medium defining game from ND. Hopefully.
No, really, they (2017 and 2019) were not great years. There were some games that were good, but most of them were niche and generally no exceptional RPG or otherwise single player game was released in those years. In terms of really good games and pushing the envelope, we got almost nothing. That's a fact. We got some indies, some me-too rpgs, the typical franchise continuations like Assassin's Creed etc etc.
The reality is that the most advancement this gen (2013-2021) in terms of game design happened around the late 2014-2016 timeframe. Afterwards we just got typical rehashes.
I have noticed something, console generations are very helpful at noticing the general trends of game design. 1 gen is the groundbreaking gen, and another is the "repeat the previous gen with more polish". Those kind of gens follow one another.
NES (8bit) gen: The start of your typical 2D platformers, top down zeldas, and pretty much most 2D styles of game began in this era
SNES (16 bit) : The same games as the NES era but with better sprites, more colors, and more paralax backgrounds.
Playstation (32bit era): The first truly 3D games, the first cinematic games, the first multimedia games, lots of new genres that didn't exist before
Playstation 2: A more polished Playstation with a DVD player. Most types of games were just PS1 games with better graphics, fewer new genres were developed.
Playstation 3: The HD generation. Lots of things changed this gen in game design, japanese developers took a backsit and western designers came from PC and established other styles of games, also the open world reigned supreme. We didn't get many new genres but we did get a radical game design approach in most genres.
Playstation 4: The HD generation+texture pack. We didn't get much improvement over the PS3 generation. Games are just more polished versions of the previous era. Every type of game that exists in the PS4 era can be found on PS3 as well, just with lower graphics.
Playstation 5: (speculation) we are going to get bigger and better developed open worlds, better physics, destructible environments, and in general the games will begin feel more like simulations and not just gamey. I believe that AI will be much more improved this gen also. Environments will feel organic, real, not just polygons with textures.
I think this gen is going to push the envelope in gaming a lot more than the PS4 gen did.