Next gen games are not current gen games with "ultra settings". That has never been the case historically, what makes you think it will be the case in the future?
You're exactly the kind of person who would have claimed that the PS4 would never get 8Gb of RAM in 2012.
Want to take an avatar bet? I'll bet you the PS5 has more than 16Gb RAM.
PS5 won't have more than 16GB of GDDR6 imo, anything else extra will be DDR4 and used for the OS. And we've already seen what next gen looks like, it's called the Xbox One X. The only difference is you'll have higher framerates, all consoles will now have high quality textures like the X does thanks to a bigger ram pool, no more half framerate animations from afar, lod will be increased, I still expect AA to be low though compared to PC because it is too demanding. The X was just a little taste. If you wanna see next gen just load up BFV on an RTX 2080 ti with Raytracing on and you'll get a good idea of what we should be expecting.
better CPUs is what will define next gen as there isn't any new tech in the PC world right now that could be included in nextgen consoles to truly make a paradigm shift, except for ray tracing, and I don't see that happening unless Sony and MS are working on it with AMD as their secret sauce by having a separate chip designed exclusively for that (like the tensor cores do) but that would most likely bring up the cost a little.
DLSS is a thing now for a pretty good reason! 4K at a high fps is hard to reach even on very beefy GPUs, which is why even Nvidia has their own solution to upscale games in a way that gives you the feel of 4k why adding in more features like raytracing. So if PCs have to do it this way, just think about what it means for consoles!
As well, SSDs should define next gen. No more waiting 4-5 minutes for Sea of Thieves to load while on my PC it takes 30 seconds.
Improvements in the tech aren't advancing as fast as it used to. People still expect the new consoles to be 3-4 times more powerful and have 3-4 times more memory, when in reality we will most likely get 1.5-2 times max the amount of power as the mid gen refreshes. Only difference is 4k will be more of the norm and higher refresh rates will also be happening more often thanks to beefier CPUs.