Those were some of the leaps I promised were coming too (hopefully, people believe in me now ). Horizon specifically, look at the foliage/trees texture mapping and their density. All things that could not have been accomplished with such finesse on current gen machines. And remember, it's just the beginning.
The idea of diminishing returns is also a slippery slope (at least right now), because what we've just seen was effortless and still the jump is apparent. They haven't even scratched the surface (though they are taking advantage of the hardware). What went into these games is nothing compared to what will go into later ones, where the visual/technical aspects will make even these early games look vastly outdated.
We'll reach the climax of diminish returns when the effort is not met with the appropriate response. These games still floored plenty of people, even if there are those who don't see much of a difference (or look for said details).
As I always try to tell people, they don't put in what is assumed they do, and as each gen comes along, they won't have to. But, the weight of diminishing returns are inevitable and will be reach some day.
Well when I talk diminishing returns, you just have to look at how dramatic each generational leap has been under the same circumstances of minimal effort.
PS1 to PS2 was massive.
PS2 to PS3 was also massive.
PS3 to PS4 was less massive, and no where near what the previous two had been. It was still however, very noticeable with time.
PS4 to PS5 looks barely different at all to me, and many others.
There is no denying that diminishing returns is happening, and at a very fast rate. Now of course later in the gen, the leap will be more apparent. But for the first few years of the console, I don't expect much. Especially with what I have seen thus far. And that is cool with me, because at this point I am more interested in the other innovations the new tech will offer.