There is a noticeable difference in looks between early PS3/XBox 360 titles and the later ones (GTA5, The Last Of Us). This is because developers figured out the optimizations better. This has always been true, they even ported Quake2 to the PS1 at one point with lighting effects intact. This is on a console without Z-buffer, with 2mb of RAM and 33mhz CPU.
PS2 had FPS like "Black" (I believe) which had physics, and emulated shader effects without GPU shaders, etc.
Of course I suspect the more consoles become like PCs, the more complex their OS becomes, the more "features" they shove in there that nobody needs, the more plans they allow for the "PS4 PROS" and "XBOX NEOS" and various incremental upgrades, the more they develop the same thick abstraction layers between software and hardware as PC has, negating the inherent advantages of the console's direct pedal-to-the-metal approach.
