the jumps are getting smaller, but they are still massive.
the jump from Xbox One to Series X is 9x on the GPU.
the difference between Xbox and Xbox 360 was a 12x jump in GPU power. so a bigger jump, but not that much bigger.
you just can't add that much more meaningful detail to characters with such a jump.
having a jump from a circle made with 10 sides, to one with 100 sides is away more noticeable and meaningful than a jump from a 100 sided circle to a 1000 sided one.
btw, this is a circle made from 100 straight lines, alsl called a hectogon
and here is one with 1000 sides, known as a Chiliagon
do you think you'd see the difference without the red dots marking the corners?
which one is this down there?
the same is happening with game graphics.
if a character has 300k polygons or 3million polygons is not easily apparent. and that's true for general world detail, shadow detail etc.
you can see a difference, but it's getting harder