There must be an interesting looking graph in this relationship...
Games which get better tech graphics and great design increase exponentially in awesomeness, but at a certain point where the tech can't get any better, it takes a significant investment in design to keep the visuals dropping jaws. Witcher 3 is a good example, other games at the time may have had reasonably similar levels of technical graphics, but the real-time oil painting visual style of the graphics, the delicate way distance could blur and meld colors together ,etc, the way they used sound to underline every component of the environment, is what made it memorable.
Human Revolution had pretty good, but not peak, graphics for its time, but looking back I think it is probably the most visually appealing game of it's epoch - to
me - because of the design, clutter, and hand-crafted flavour of its environments. The style is what
supercharges a game's visuals. But tech is still needed to hold up its end of the bargain for the overall effect to really move us.