To be fair, that's because high end PC isn't really being targeted. A game designed from the ground up to make best use of powerful gaming rig would be substantially better than what's actually available which is mostly about scaling up with minimal effort from a lower common denominator. But yes, a two fold increase perofrmance doesn't equate to a 2x increase in on screen wow. Wow is on a logarithmic curve.
This was very much in evidence on PC when the new console generation came out. For many developers/publishers there was an immediate larger than "normal" jump in visual quality despite PC hardware not changing significantly relative to any other hardware generation change on PC during the X360/PS3 years.
There are points of diminishing returns, obviously, but there's also relatively untapped area's for massive improvements. Lighting for example is still mostly limited by consoles and past generations of hardware on PC. Regardless of the lighting solution chosen, it has to be able to run on consoles and it has to be able to run in some capacity on years old graphics hardware on PC (although even on PC, you'll see some developers just chose a hardware generation "cut-off" in order to not be limited by that generation of hardware).
What does this mean for consoles. Just like PS3/X360 to PS4/XBO didn't see a 1:1 increase in graphics quality compared to GPU power, it obviously won't happen with Neo or Scorpio either. However, unlike PS3/X360 to PS4/XBO not every developer or even most developers are likely to target Neo or Scorpio.
Most developers will continue to target base PS4/XBO and then either increase resolution, increase FPS, or increase the quality/complexity of the existing shaders. Similar to console to PC ports. VR developer's are far more likely to do the reverse, however. Target Neo and downgrade as much as possible to possible to support PS4. That's mostly due to the fact that the PS4 is fairly underpowered with regards to VR. At least for anything other than relatively simplistic games.
That will most likely change with the consoles after the Neo/Scorpio. At that point NEO/Scorpio become the new targets for most developers while the new consoles are only targeted by a few developer.
We'll end up seeing a more graduated progression in graphics quality rather than a drastic increase as in past generations. However, by the time a certain console hardware configuration becomes the target for development it should match fairly closes the time it would have taken that generation to become the target anyway.
IE.
PS4 - > Neo (gradual increase) -> PS5 (gradual increase) -> PS5+ (gradual increase) -> etc.
But
PS4 -> PS5 (big increase)
NEO -> PS5+ (big increase)
For Xbox side, just replace with Xbox variants. Basically it just becomes more PC like, but in general better overall than in the past as PC won't be limited as much by consoles during the traditional middle of a console generation. The entire gaming industry (console + PC) will gradually increase in quality in relatively small time increments. Versus the entire graphics industry (console + PC) only having large increases (lurches) after a large time increment.
Regards,
SB