To me, the biggest deal last gen that made PC gaming so wonderful was image quality.
I built my pc in late 2012 with a 670 GTX.
What this meant to me back then was jumping from PlayStation 3's often seen 720p with unstable 30fps and weird anti aliasing solutions (i.e. The Last of Us which came out a few months after that and still is my favorite game of all time) to downsampled 1440p, 60fps and at least FXAA.
What a huge jump. It was hard to go back.
Now I get to go through DMC 5 at 4K 60fps on my Xbox One X.
It was always about image quality, textures, good AA solutions, stable frame rates.
I don't really need 144hz or modding or whatever else PC can offer (all of which is fucking awesome, of course). And I do lament Bloodborne being stuck at 1080 30fps, but that was 2015.
In 2019 I'm not as excited to spend more than 1k € to enjoy 4K gaming for a while until my rig's obsolete like my 670.
I had to move on from 720p in 2012 but I'm fully satisfied with 4K, even checkerboard, and console VR in 2019.
For consoles, everything improved so much during this generation when it comes to Anisotropic Filtering, Ambient Occlusion, Anti Aliasing, tesselation, shadows, particles, etc. that were previously effects I'd only properly enjoy on a good pc in 2012.
But now even if there's always an EXTREME option for high end gaming rigs, at least console games don't have nothing or badly implemented solutions. The newest engines really are amazing at what they do and I hope ray tracing won't take too many years to be mainstream.